DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Mercurial (b6d82b1a6b02)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
 * A base class implementing nsIObjectLoadingContent for use by
 * various content nodes that want to provide plugin/document/image
 * loading functionality (eg <embed>, <object>, etc).
 */

#ifndef NSOBJECTLOADINGCONTENT_H_
#define NSOBJECTLOADINGCONTENT_H_

#include "mozilla/Attributes.h"
#include "mozilla/dom/BindingDeclarations.h"
#include "nsImageLoadingContent.h"
#include "nsIStreamListener.h"
#include "nsIChannelEventSink.h"
#include "nsIContentPolicy.h"
#include "nsIObjectLoadingContent.h"
#include "nsIRunnable.h"
#include "nsIThreadInternal.h"
#include "nsIFrame.h"
#include "nsFrameLoaderOwner.h"

class nsAsyncInstantiateEvent;
class nsStopPluginRunnable;
class AutoSetInstantiatingToFalse;
class nsIPrincipal;
class nsFrameLoader;
class nsPluginFrame;
class nsPluginInstanceOwner;

namespace mozilla {
namespace dom {
struct BindContext;
template <typename T>
class Sequence;
struct MozPluginParameter;
class HTMLIFrameElement;
template <typename T>
struct Nullable;
class WindowProxyHolder;
class XULFrameElement;
}  // namespace dom
}  // namespace mozilla

class nsObjectLoadingContent : public nsImageLoadingContent,
                               public nsIStreamListener,
                               public nsFrameLoaderOwner,
                               public nsIObjectLoadingContent,
                               public nsIChannelEventSink {
  friend class AutoSetInstantiatingToFalse;
  friend class AutoSetLoadingToFalse;
  friend class CheckPluginStopEvent;
  friend class nsStopPluginRunnable;
  friend class nsAsyncInstantiateEvent;

 public:
  // This enum's values must be the same as the constants on
  // nsIObjectLoadingContent
  enum ObjectType {
    // Loading, type not yet known. We may be waiting for a channel to open.
    eType_Loading = TYPE_LOADING,
    // Content is a *non-svg* image
    eType_Image = TYPE_IMAGE,
    // Content is a plugin
    eType_Plugin = TYPE_PLUGIN,
    // Content is a fake plugin, which loads as a document but behaves as a
    // plugin (see nsPluginHost::CreateFakePlugin)
    eType_FakePlugin = TYPE_FAKE_PLUGIN,
    // Content is a subdocument, possibly SVG
    eType_Document = TYPE_DOCUMENT,
    // No content loaded (fallback). May be showing alternate content or
    // a custom error handler - *including* click-to-play dialogs
    eType_Null = TYPE_NULL
  };

  enum FallbackType {
    // The content type is not supported (e.g. plugin not installed)
    eFallbackUnsupported = nsIObjectLoadingContent::PLUGIN_UNSUPPORTED,
    // Showing alternate content
    eFallbackAlternate = nsIObjectLoadingContent::PLUGIN_ALTERNATE,
    // The plugin exists, but is disabled
    eFallbackDisabled = nsIObjectLoadingContent::PLUGIN_DISABLED,
    // The plugin is blocklisted and disabled
    eFallbackBlocklisted = nsIObjectLoadingContent::PLUGIN_BLOCKLISTED,
    // The plugin is considered outdated, but not disabled
    eFallbackOutdated = nsIObjectLoadingContent::PLUGIN_OUTDATED,
    // The plugin has crashed
    eFallbackCrashed = nsIObjectLoadingContent::PLUGIN_CRASHED,
    // Suppressed by security policy
    eFallbackSuppressed = nsIObjectLoadingContent::PLUGIN_SUPPRESSED,
    // Blocked by content policy
    eFallbackUserDisabled = nsIObjectLoadingContent::PLUGIN_USER_DISABLED,
    /// ** All values >= eFallbackClickToPlay are plugin placeholder types
    ///    that would be replaced by a real plugin if activated (PlayPlugin())
    /// ** Furthermore, values >= eFallbackClickToPlay and
    ///    <= eFallbackClickToPlayQuiet are click-to-play types.
    // The plugin is disabled until the user clicks on it
    eFallbackClickToPlay = nsIObjectLoadingContent::PLUGIN_CLICK_TO_PLAY,
    // The plugin is vulnerable (update available)
    eFallbackVulnerableUpdatable =
        nsIObjectLoadingContent::PLUGIN_VULNERABLE_UPDATABLE,
    // The plugin is vulnerable (no update available)
    eFallbackVulnerableNoUpdate =
        nsIObjectLoadingContent::PLUGIN_VULNERABLE_NO_UPDATE,
    // The plugin is click-to-play, but the user won't see overlays
    eFallbackClickToPlayQuiet =
        nsIObjectLoadingContent::PLUGIN_CLICK_TO_PLAY_QUIET,
  };

  nsObjectLoadingContent();
  virtual ~nsObjectLoadingContent();

  NS_DECL_NSIREQUESTOBSERVER
  NS_DECL_NSISTREAMLISTENER
  NS_DECL_NSIOBJECTLOADINGCONTENT
  NS_DECL_NSICHANNELEVENTSINK

  /**
   * Object state. This is a bitmask of NS_EVENT_STATEs epresenting the
   * current state of the object.
   */
  mozilla::EventStates ObjectState() const;

  ObjectType Type() const { return mType; }

  void SetIsNetworkCreated(bool aNetworkCreated) {
    mNetworkCreated = aNetworkCreated;
  }

  /**
   * When the object is loaded, the attributes and all nested <param>
   * elements are cached as name:value string pairs to be passed as
   * parameters when instantiating the plugin.
   *
   * Note: these cached values can be overriden for different quirk cases.
   */
  // Returns the cached attributes array.
  void GetPluginAttributes(
      nsTArray<mozilla::dom::MozPluginParameter>& aAttributes);

  // Returns the cached <param> array.
  void GetPluginParameters(
      nsTArray<mozilla::dom::MozPluginParameter>& aParameters);

  /**
   * Immediately instantiate a plugin instance. This is a no-op if mType !=
   * eType_Plugin or a plugin is already running.
   *
   * aIsLoading indicates that we are in the loading code, and we can bypass
   * the mIsLoading check.
   */
  nsresult InstantiatePluginInstance(bool aIsLoading = false);

  /**
   * Notify this class the document state has changed
   * Called by Document so we may suspend plugins in inactive documents)
   */
  void NotifyOwnerDocumentActivityChanged();

  /**
   * When a plug-in is instantiated, it can create a scriptable
   * object that the page wants to interact with.  We expose this
   * object by placing it on the prototype chain of our element,
   * between the element itself and its most-derived DOM prototype.
   *
   * SetupProtoChain handles actually inserting the plug-in
   * scriptable object into the proto chain if needed.
   *
   * DoResolve is a hook that allows us to find out when the web
   * page is looking up a property name on our object and make sure
   * that our plug-in, if any, is instantiated.
   */
  // Helper for WebIDL node wrapping
  void SetupProtoChain(JSContext* aCx, JS::Handle<JSObject*> aObject);

  // Remove plugin from protochain
  void TeardownProtoChain();

  // Helper for WebIDL NeedResolve
  bool DoResolve(JSContext* aCx, JS::Handle<JSObject*> aObject,
                 JS::Handle<jsid> aId,
                 JS::MutableHandle<JS::PropertyDescriptor> aDesc);
  // The return value is whether DoResolve might end up resolving the given
  // id.  If in doubt, return true.
  static bool MayResolve(jsid aId);

  // Helper for WebIDL enumeration
  void GetOwnPropertyNames(JSContext* aCx,
                           JS::MutableHandleVector<jsid> /* unused */,
                           bool /* unused */, mozilla::ErrorResult& aRv);

  // WebIDL API
  mozilla::dom::Document* GetContentDocument(nsIPrincipal& aSubjectPrincipal);
  void GetActualType(nsAString& aType) const {
    CopyUTF8toUTF16(mContentType, aType);
  }
  uint32_t DisplayedType() const { return mType; }
  uint32_t GetContentTypeForMIMEType(const nsAString& aMIMEType) {
    return GetTypeOfContent(NS_ConvertUTF16toUTF8(aMIMEType), false);
  }
  void PlayPlugin(mozilla::dom::SystemCallerGuarantee,
                  mozilla::ErrorResult& aRv);
  void Reload(bool aClearActivation, mozilla::ErrorResult& aRv) {
    aRv = Reload(aClearActivation);
  }
  bool Activated() const { return mActivated; }
  nsIURI* GetSrcURI() const { return mURI; }

  /**
   * The default state that this plugin would be without manual activation.
   * @returns PLUGIN_ACTIVE if the default state would be active.
   */
  uint32_t DefaultFallbackType();

  uint32_t PluginFallbackType() const { return mFallbackType; }
  bool HasRunningPlugin() const { return !!mInstanceOwner; }
  // FIXME rename this
  void SkipFakePlugins(mozilla::ErrorResult& aRv) { aRv = SkipFakePlugins(); }
  void SwapFrameLoaders(mozilla::dom::HTMLIFrameElement& aOtherLoaderOwner,
                        mozilla::ErrorResult& aRv) {
    aRv.Throw(NS_ERROR_NOT_IMPLEMENTED);
  }
  void SwapFrameLoaders(mozilla::dom::XULFrameElement& aOtherLoaderOwner,
                        mozilla::ErrorResult& aRv) {
    aRv.Throw(NS_ERROR_NOT_IMPLEMENTED);
  }

  uint32_t GetRunID(mozilla::dom::SystemCallerGuarantee,
                    mozilla::ErrorResult& aRv);

  bool IsRewrittenYoutubeEmbed() const { return mRewrittenYoutubeEmbed; }

  void PresetOpenerWindow(const mozilla::dom::Nullable<
                              mozilla::dom::WindowProxyHolder>& aOpenerWindow,
                          mozilla::ErrorResult& aRv);

 protected:
  /**
   * Begins loading the object when called
   *
   * Attributes of |this| QI'd to nsIContent will be inspected, depending on
   * the node type. This function currently assumes it is a <object> or
   * <embed> tag.
   *
   * The instantiated plugin depends on:
   * - The URI (<embed src>, <object data>)
   * - The type 'hint' (type attribute)
   * - The mime type returned by opening the URI
   * - Enabled plugins claiming the ultimate mime type
   * - The capabilities returned by GetCapabilities
   * - The classid attribute, if eFallbackIfClassIDPresent is among the
   * capabilities
   *
   * If eAllowPluginSkipChannel is true, we may skip opening the URI if our
   * type hint points to a valid plugin, deferring that responsibility to the
   * plugin.
   * Similarly, if no URI is provided, but a type hint for a valid plugin is
   * present, that plugin will be instantiated
   *
   * Otherwise a request to that URI is made and the type sent by the server
   * is used to find a suitable handler, EXCEPT when:
   *  - The type hint refers to a *supported* plugin, in which case that
   *    plugin will be instantiated regardless of the server provided type
   *  - The server returns a binary-stream type, and our type hint refers to
   *    a valid non-document type, we will use the type hint
   *
   * @param aNotify    If we should send notifications. If false, content
   *                   loading may be deferred while appropriate frames are
   *                   created
   * @param aForceLoad If we should reload this content (and re-attempt the
   *                   channel open) even if our parameters did not change
   */
  nsresult LoadObject(bool aNotify, bool aForceLoad = false);

  enum Capabilities {
    eSupportImages = 1u << 0,     // Images are supported (imgILoader)
    eSupportPlugins = 1u << 1,    // Plugins are supported (nsIPluginHost)
    eSupportDocuments = 1u << 2,  // Documents are supported
                                  // (DocumentLoaderFactory)
                                  // This flag always includes SVG

    // Node supports class ID as an attribute, and should fallback if it is
    // present, as class IDs are not supported.
    eFallbackIfClassIDPresent = 1u << 3,

    // If possible to get a *plugin* type from the type attribute *or* file
    // extension, we can use that type and begin loading the plugin before
    // opening a channel.
    // A side effect of this is if the channel fails, the plugin is still
    // running.
    eAllowPluginSkipChannel = 1u << 4
  };

  /**
   * Returns the list of capabilities this content node supports. This is a
   * bitmask consisting of flags from the Capabilities enum.
   *
   * The default implementation supports all types but not
   * eSupportClassID or eAllowPluginSkipChannel
   */
  virtual uint32_t GetCapabilities() const;

  /**
   * Destroys all loaded documents/plugins and releases references
   */
  void DestroyContent();

  static void Traverse(nsObjectLoadingContent* tmp,
                       nsCycleCollectionTraversalCallback& cb);

  void CreateStaticClone(nsObjectLoadingContent* aDest) const;

  void DoStopPlugin(nsPluginInstanceOwner* aInstanceOwner);

  nsresult BindToTree(mozilla::dom::BindContext&, nsINode& aParent);
  void UnbindFromTree(bool aNullParent = true);

  /**
   * Return the content policy type used for loading the element.
   */
  virtual nsContentPolicyType GetContentPolicyType() const = 0;

  /**
   * Decides whether we should load <embed>/<object> node content.
   *
   * If this is an <embed> or <object> node there are cases in which we should
   * not try to load the content:
   *
   * - If the node is the child of a media element
   * - If the node is the child of an <object> node that already has
   *   content being loaded.
   *
   * In these cases, this function will return false, which will cause
   * us to skip calling LoadObject.
   */
  bool BlockEmbedOrObjectContentLoading();

 private:
  // Object parameter changes returned by UpdateObjectParameters
  enum ParameterUpdateFlags {
    eParamNoChange = 0,
    // Parameters that potentially affect the channel changed
    // - mOriginalURI, mOriginalContentType
    eParamChannelChanged = 1u << 0,
    // Parameters that affect displayed content changed
    // - mURI, mContentType, mType, mBaseURI
    eParamStateChanged = 1u << 1,
    // The effective content type changed, independant of object type. This
    // can happen when changing from Loading -> Final type, but doesn't
    // necessarily happen when changing between object types. E.g., if a PDF
    // handler was installed between the last load of this object and now, we
    // might change from eType_Document -> eType_Plugin without changing
    // ContentType
    eParamContentTypeChanged = 1u << 2
  };

  /**
   * Getter for child <param> elements that are not nested in another plugin
   * dom element.
   * This is an internal helper function and should not be used directly for
   * passing parameters to the plugin instance.
   *
   * See GetPluginParameters and GetPluginAttributes, which also handle
   * quirk-overrides.
   *
   * @param aParameters     The array containing pairs of name/value strings
   *                        from nested <param> objects.
   */
  void GetNestedParams(nsTArray<mozilla::dom::MozPluginParameter>& aParameters);

  MOZ_MUST_USE nsresult BuildParametersArray();

  /**
   * Loads fallback content with the specified FallbackType
   *
   * @param aType   FallbackType value for type of fallback we're loading
   * @param aNotify Send notifications and events. If false, caller is
   *                responsible for doing so
   */
  void LoadFallback(FallbackType aType, bool aNotify);

  /**
   * Internal version of LoadObject that should only be used by this class
   * aLoadingChannel is passed by the LoadObject call from OnStartRequest,
   * primarily for sanity-preservation
   */
  nsresult LoadObject(bool aNotify, bool aForceLoad,
                      nsIRequest* aLoadingChannel);

  /**
   * Introspects the object and sets the following member variables:
   * - mOriginalContentType : This is the type attribute on the element
   * - mOriginalURI         : The src or data attribute on the element
   * - mURI                 : The final URI, considering mChannel if
   *                          mChannelLoaded is set
   * - mContentType         : The final content type, considering mChannel if
   *                          mChannelLoaded is set
   * - mBaseURI             : The object's base URI, which may be set by the
   *                          object
   * - mType                : The type the object is determined to be based
   *                          on the above
   *
   * NOTE The class assumes that mType is the currently loaded type at various
   *      points, so the caller of this function must take the appropriate
   *      actions to ensure this
   *
   * NOTE This function does not perform security checks, only determining the
   *      requested type and parameters of the object.
   *
   * @return Returns a bitmask of ParameterUpdateFlags values
   */
  ParameterUpdateFlags UpdateObjectParameters();

  /**
   * Queue a CheckPluginStopEvent and track it in mPendingCheckPluginStopEvent
   */
  void QueueCheckPluginStopEvent();

  void NotifyContentObjectWrapper();

  /**
   * Opens the channel pointed to by mURI into mChannel.
   */
  nsresult OpenChannel();

  /**
   * Closes and releases references to mChannel and, if opened, mFinalListener
   */
  nsresult CloseChannel();

  /**
   * If this object should be tested against blocking list.
   */
  bool ShouldBlockContent();

  /**
   * If this object is allowed to play plugin content, or if it would display
   * click-to-play instead.
   * NOTE that this does not actually check if the object is a loadable plugin
   * NOTE This ignores the current activated state. The caller should check
   *      this if appropriate.
   */
  bool ShouldPlay(FallbackType& aReason);

  /**
   * This method tells if the fallback content should be attempted to be used
   * over the original object content.
   * It will look at prefs and this plugin's CTP state to make a decision.
   *
   * NOTE that this doesn't say whether the fallback _will_ be used, only
   * whether we should look into it to possibly use it. The final answer will be
   * given by the PreferFallback method.
   *
   * @param aIsPluginClickToPlay Whether this object instance is CTP.
   */
  bool FavorFallbackMode(bool aIsPluginClickToPlay);

  /**
   * Whether the page has provided good fallback content to this object.
   */
  bool HasGoodFallback();

  /**
   * This method tells the final answer on whether this object's fallback
   * content should be used instead of the original plugin content.
   *
   * @param aIsPluginClickToPlay Whether this object instance is CTP.
   */
  bool PreferFallback(bool aIsPluginClickToPlay);

  /**
   * Helper to check if our current URI passes policy
   *
   * @param aContentPolicy [out] The result of the content policy decision
   *
   * @return true if call succeeded and NS_CP_ACCEPTED(*aContentPolicy)
   */
  bool CheckLoadPolicy(int16_t* aContentPolicy);

  /**
   * Helper to check if the object passes process policy. Assumes we have a
   * final determined type.
   *
   * @param aContentPolicy [out] The result of the content policy decision
   *
   * @return true if call succeeded and NS_CP_ACCEPTED(*aContentPolicy)
   */
  bool CheckProcessPolicy(int16_t* aContentPolicy);

  /**
   * Gets the plugin instance and creates a plugin stream listener, assigning
   * it to mFinalListener
   */
  bool MakePluginListener();

  void SetupFrameLoader(int32_t aJSPluginId);

  /**
   * Helper to spawn mFrameLoader and return a pointer to its docshell
   *
   * @param aURI URI we intend to load for the recursive load check (does not
   *             actually load anything)
   */
  already_AddRefed<nsIDocShell> SetupDocShell(nsIURI* aRecursionCheckURI);

  /**
   * Unloads all content and resets the object to a completely unloaded state
   *
   * NOTE Calls StopPluginInstance() and may spin the event loop
   *
   * @param aResetState Reset the object type to 'loading' and destroy channel
   *                    as well
   */
  void UnloadObject(bool aResetState = true);

  /**
   * Notifies document observes about a new type/state of this object.
   * Triggers frame construction as needed. mType must be set correctly when
   * this method is called. This method is cheap if the type and state didn't
   * actually change.
   *
   * @param aSync If a synchronous frame construction is required. If false,
   *              the construction may either be sync or async.
   * @param aNotify if false, only need to update the state of our element.
   */
  void NotifyStateChanged(ObjectType aOldType, mozilla::EventStates aOldState,
                          bool aSync, bool aNotify);

  /**
   * Returns a ObjectType value corresponding to the type of content we would
   * support the given MIME type as, taking capabilities and plugin state
   * into account
   *
   * @param aNoFakePlugin Don't select a fake plugin handler as a valid type,
   *                      as when SkipFakePlugins() is called.
   * @return The ObjectType enum value that we would attempt to load
   *
   * NOTE this does not consider whether the content would be suppressed by
   *      click-to-play or other content policy checks
   */
  ObjectType GetTypeOfContent(const nsCString& aMIMEType, bool aNoFakePlugin);

  /**
   * Gets the frame that's associated with this content node.
   * Does not flush.
   */
  nsPluginFrame* GetExistingFrame();

  /**
   * Used for identifying whether we can rewrite a youtube flash embed to
   * possibly use HTML5 instead.
   *
   * Returns true if plugin.rewrite_youtube_embeds pref is true and the
   * element this nsObjectLoadingContent instance represents:
   *
   * - is an embed or object node
   * - has a URL pointing at the youtube.com domain, using "/v/" style video
   *   path reference.
   *
   * Having the enablejsapi flag means the document that contains the element
   * could possibly be manipulating the youtube video elsewhere on the page
   * via javascript. In the context of embed elements, this usage has been
   * deprecated by youtube, so we can just rewrite as normal.
   *
   * If we can rewrite the URL, we change the "/v/" to "/embed/", and change
   * our type to eType_Document so that we render similarly to an iframe
   * embed.
   */
  void MaybeRewriteYoutubeEmbed(nsIURI* aURI, nsIURI* aBaseURI,
                                nsIURI** aRewrittenURI);

  // Helper class for SetupProtoChain
  class SetupProtoChainRunner final : public nsIRunnable {
    ~SetupProtoChainRunner() = default;

   public:
    NS_DECL_ISUPPORTS

    explicit SetupProtoChainRunner(nsObjectLoadingContent* aContent);

    NS_IMETHOD Run() override;

   private:
    // We store an nsIObjectLoadingContent because we can
    // unambiguously refcount that.
    RefPtr<nsIObjectLoadingContent> mContent;
  };

  // Utility getter for getting our nsNPAPIPluginInstance in a safe way.
  nsNPAPIPluginInstance* ScriptRequestPluginInstance(JSContext* aCx);

  // Utility method for getting our plugin JSObject
  static nsresult GetPluginJSObject(JSContext* cx,
                                    nsNPAPIPluginInstance* plugin_inst,
                                    JS::MutableHandle<JSObject*> plugin_obj,
                                    JS::MutableHandle<JSObject*> plugin_proto);

  // Utility for firing an error event, if we're an <object>.
  void MaybeFireErrorEvent();

  // The final listener for mChannel (uriloader, pluginstreamlistener, etc.)
  nsCOMPtr<nsIStreamListener> mFinalListener;

  // Track if we have a pending AsyncInstantiateEvent
  nsCOMPtr<nsIRunnable> mPendingInstantiateEvent;

  // Tracks if we have a pending CheckPluginStopEvent
  nsCOMPtr<nsIRunnable> mPendingCheckPluginStopEvent;

  // The content type of our current load target, updated by
  // UpdateObjectParameters(). Takes the channel's type into account once
  // opened.
  //
  // May change if a channel is opened, does not imply a loaded state
  nsCString mContentType;

  // The content type 'hint' provided by the element's type attribute. May
  // or may not be used as a final type
  nsCString mOriginalContentType;

  // The channel that's currently being loaded. If set, but mChannelLoaded is
  // false, has not yet reached OnStartRequest
  nsCOMPtr<nsIChannel> mChannel;

  // The URI of the current content.
  // May change as we open channels and encounter redirects - does not imply
  // a loaded type
  nsCOMPtr<nsIURI> mURI;

  // The original URI obtained from inspecting the element. May differ from
  // mURI due to redirects
  nsCOMPtr<nsIURI> mOriginalURI;

  // The baseURI used for constructing mURI.
  nsCOMPtr<nsIURI> mBaseURI;

  // Type of the currently-loaded content.
  ObjectType mType : 8;
  // The type of fallback content we're showing (see ObjectState())
  FallbackType mFallbackType : 8;

  uint32_t mRunID;
  bool mHasRunID : 1;

  // If true, we have opened a channel as the listener and it has reached
  // OnStartRequest. Does not get set for channels that are passed directly to
  // the plugin listener.
  bool mChannelLoaded : 1;

  // Whether we are about to call instantiate on our frame. If we aren't,
  // SetFrame needs to asynchronously call Instantiate.
  bool mInstantiating : 1;

  // True when the object is created for an element which the parser has
  // created using NS_FROM_PARSER_NETWORK flag. If the element is modified,
  // it may lose the flag.
  bool mNetworkCreated : 1;

  // Used to keep track of whether or not a plugin has been explicitly
  // activated by PlayPlugin(). (see ShouldPlay())
  bool mActivated : 1;

  // Whether content blocking is enabled or not for this object.
  bool mContentBlockingEnabled : 1;

  // If we should not use fake plugins until the next type change
  bool mSkipFakePlugins : 1;

  // Protects DoStopPlugin from reentry (bug 724781).
  bool mIsStopping : 1;

  // Protects LoadObject from re-entry
  bool mIsLoading : 1;

  // For plugin stand-in types (click-to-play) tracks whether content js has
  // tried to access the plugin script object.
  bool mScriptRequested : 1;

  // True if object represents an object/embed tag pointing to a flash embed
  // for a youtube video. When possible (see IsRewritableYoutubeEmbed function
  // comments for details), we change these to try to load HTML5 versions of
  // videos.
  bool mRewrittenYoutubeEmbed : 1;

  // Cache the answer of PreferFallback() because ShouldPlay is called several
  // times during the load process.
  bool mPreferFallback : 1;
  bool mPreferFallbackKnown : 1;

  WeakFrame mPrintFrame;

  RefPtr<nsPluginInstanceOwner> mInstanceOwner;
  nsTArray<mozilla::dom::MozPluginParameter> mCachedAttributes;
  nsTArray<mozilla::dom::MozPluginParameter> mCachedParameters;
};

#endif