gfx/layers/ipc/CompositorBridgeParent.h
author Phil Ringnalda <philringnalda@gmail.com>
Wed, 29 Jun 2016 19:35:24 -0700
changeset 303220 48bd14a01b55464215c0bfe973f5657a7b5b7f9c
parent 303201 d806fac2c856f7c7f08049eb0eefbabba7283939
child 303383 0cbb330c02c75657c3f4f9265d705217bb005c5b
permissions -rw-r--r--
Back out 7 changesets (bug 1281998) for Windows Marionette crashes Backed out changeset d806fac2c856 (bug 1281998) Backed out changeset b8d4fedfd7eb (bug 1281998) Backed out changeset a72929c0c3ec (bug 1281998) Backed out changeset 74198f88fa37 (bug 1281998) Backed out changeset 54a0e73f6906 (bug 1281998) Backed out changeset 99d1da1293b7 (bug 1281998) Backed out changeset a5a9585754b1 (bug 1281998)

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set sw=4 ts=8 et 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/. */

#ifndef mozilla_layers_CompositorBridgeParent_h
#define mozilla_layers_CompositorBridgeParent_h

// Enable this pref to turn on compositor performance warning.
// This will print warnings if the compositor isn't meeting
// its responsiveness objectives:
//    1) Compose a frame within 15ms of receiving a ScheduleCompositeCall
//    2) Unless a frame was composited within the throttle threshold in
//       which the deadline will be 15ms + throttle threshold
//#define COMPOSITOR_PERFORMANCE_WARNING

#include <stdint.h>                     // for uint64_t
#include "Layers.h"                     // for Layer
#include "mozilla/Assertions.h"         // for MOZ_ASSERT_HELPER2
#include "mozilla/Attributes.h"         // for override
#include "mozilla/Maybe.h"
#include "mozilla/Monitor.h"            // for Monitor
#include "mozilla/RefPtr.h"             // for RefPtr
#include "mozilla/TimeStamp.h"          // for TimeStamp
#include "mozilla/dom/ipc/IdType.h"
#include "mozilla/gfx/Point.h"          // for IntSize
#include "mozilla/ipc/ProtocolUtils.h"
#include "mozilla/ipc/SharedMemory.h"
#include "mozilla/layers/GeckoContentController.h"
#include "mozilla/layers/ISurfaceAllocator.h" // for ShmemAllocator
#include "mozilla/layers/LayersMessages.h"  // for TargetConfig
#include "mozilla/layers/PCompositorBridgeParent.h"
#include "mozilla/layers/ShadowLayersManager.h" // for ShadowLayersManager
#include "mozilla/layers/APZTestData.h"
#include "nsISupportsImpl.h"
#include "ThreadSafeRefcountingWithMainThreadDestruction.h"
#include "mozilla/VsyncDispatcher.h"
#include "CompositorWidgetProxy.h"

class MessageLoop;
class nsIWidget;

namespace mozilla {

class CancelableRunnable;

namespace gfx {
class DrawTarget;
class GPUProcessManager;
} // namespace gfx

namespace ipc {
class Shmem;
} // namespace ipc

namespace layers {

class APZCTreeManager;
class AsyncCompositionManager;
class Compositor;
class CompositorBridgeParent;
class LayerManagerComposite;
class LayerTransactionParent;
class PAPZParent;
class CrossProcessCompositorBridgeParent;
class CompositorThreadHolder;
class InProcessCompositorSession;

struct ScopedLayerTreeRegistration
{
  ScopedLayerTreeRegistration(APZCTreeManager* aApzctm,
                              uint64_t aLayersId,
                              Layer* aRoot,
                              GeckoContentController* aController);
  ~ScopedLayerTreeRegistration();

private:
  uint64_t mLayersId;
};

/**
 * Manages the vsync (de)registration and tracking on behalf of the
 * compositor when it need to paint.
 * Turns vsync notifications into scheduled composites.
 **/
class CompositorVsyncScheduler
{
  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CompositorVsyncScheduler)

public:
  explicit CompositorVsyncScheduler(CompositorBridgeParent* aCompositorBridgeParent,
                                    widget::CompositorWidgetProxy* aWidgetProxy);

#ifdef MOZ_WIDGET_GONK
  // emulator-ics never trigger the display on/off, so compositor will always
  // skip composition request at that device. Only check the display status
  // with kk device and upon.
#if ANDROID_VERSION >= 19
  // SetDisplay() and CancelSetDisplayTask() are used for the display on/off.
  // It will clear all composition related task and flag, and skip another
  // composition task during the display off. That could prevent the problem
  // that compositor might show the old content at the first frame of display on.
  void SetDisplay(bool aDisplayEnable);
#endif
#endif

  bool NotifyVsync(TimeStamp aVsyncTimestamp);
  void SetNeedsComposite();
  void OnForceComposeToTarget();

  void ScheduleTask(already_AddRefed<CancelableRunnable>, int);
  void ResumeComposition();
  void ComposeToTarget(gfx::DrawTarget* aTarget, const gfx::IntRect* aRect = nullptr);
  void PostCompositeTask(TimeStamp aCompositeTimestamp);
  void Destroy();
  void ScheduleComposition();
  void CancelCurrentCompositeTask();
  bool NeedsComposite();
  void Composite(TimeStamp aVsyncTimestamp);
  void ForceComposeToTarget(gfx::DrawTarget* aTarget, const gfx::IntRect* aRect);

  const TimeStamp& GetLastComposeTime()
  {
    return mLastCompose;
  }

#ifdef COMPOSITOR_PERFORMANCE_WARNING
  const TimeStamp& GetExpectedComposeStartTime()
  {
    return mExpectedComposeStartTime;
  }
#endif

private:
  virtual ~CompositorVsyncScheduler();

  void NotifyCompositeTaskExecuted();
  void ObserveVsync();
  void UnobserveVsync();
  void DispatchTouchEvents(TimeStamp aVsyncTimestamp);
  void DispatchVREvents(TimeStamp aVsyncTimestamp);
  void CancelCurrentSetNeedsCompositeTask();
#ifdef MOZ_WIDGET_GONK
#if ANDROID_VERSION >= 19
  void CancelSetDisplayTask();
#endif
#endif

  class Observer final : public VsyncObserver
  {
  public:
    explicit Observer(CompositorVsyncScheduler* aOwner);
    virtual bool NotifyVsync(TimeStamp aVsyncTimestamp) override;
    void Destroy();
  private:
    virtual ~Observer();

    Mutex mMutex;
    // Hold raw pointer to avoid mutual reference.
    CompositorVsyncScheduler* mOwner;
  };

  CompositorBridgeParent* mCompositorBridgeParent;
  TimeStamp mLastCompose;

#ifdef COMPOSITOR_PERFORMANCE_WARNING
  TimeStamp mExpectedComposeStartTime;
#endif

  bool mAsapScheduling;
  bool mIsObservingVsync;
  uint32_t mNeedsComposite;
  int32_t mVsyncNotificationsSkipped;
  RefPtr<CompositorVsyncDispatcher> mCompositorVsyncDispatcher;
  RefPtr<CompositorVsyncScheduler::Observer> mVsyncObserver;

  mozilla::Monitor mCurrentCompositeTaskMonitor;
  RefPtr<CancelableRunnable> mCurrentCompositeTask;

  mozilla::Monitor mSetNeedsCompositeMonitor;
  RefPtr<CancelableRunnable> mSetNeedsCompositeTask;

#ifdef MOZ_WIDGET_GONK
#if ANDROID_VERSION >= 19
  bool mDisplayEnabled;
  mozilla::Monitor mSetDisplayMonitor;
  RefPtr<CancelableRunnable> mSetDisplayTask;
#endif
#endif
};

class CompositorUpdateObserver
{
public:
  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CompositorUpdateObserver);

  virtual void ObserveUpdate(uint64_t aLayersId, bool aActive) = 0;

protected:
  virtual ~CompositorUpdateObserver() {}
};

class CompositorBridgeParent final : public PCompositorBridgeParent,
                                     public ShadowLayersManager,
                                     public CompositorBridgeParentIPCAllocator,
                                     public ShmemAllocator
{
  friend class CompositorVsyncScheduler;
  friend class CompositorThreadHolder;
  friend class InProcessCompositorSession;
  friend class gfx::GPUProcessManager;

public:
  explicit CompositorBridgeParent(widget::CompositorWidgetProxy* aWidget,
                                  CSSToLayoutDeviceScale aScale,
                                  bool aUseAPZ,
                                  bool aUseExternalSurfaceSize,
                                  const gfx::IntSize& aSurfaceSize);

  virtual bool RecvGetFrameUniformity(FrameUniformityData* aOutData) override;
  virtual bool RecvRequestOverfill() override;
  virtual bool RecvWillClose() override;
  virtual bool RecvPause() override;
  virtual bool RecvResume() override;
  virtual bool RecvNotifyHidden(const uint64_t& id) override { return true; }
  virtual bool RecvNotifyVisible(const uint64_t& id) override { return true; }
  virtual bool RecvNotifyChildCreated(const uint64_t& child) override;
  virtual bool RecvAdoptChild(const uint64_t& child) override;
  virtual bool RecvMakeSnapshot(const SurfaceDescriptor& aInSnapshot,
                                const gfx::IntRect& aRect) override;
  virtual bool RecvFlushRendering() override;
  virtual bool RecvForcePresent() override;

  virtual bool RecvAcknowledgeCompositorUpdate(const uint64_t& aLayersId) override {
    MOZ_ASSERT_UNREACHABLE("This message is only sent cross-process");
    return true;
  }

  virtual bool RecvGetTileSize(int32_t* aWidth, int32_t* aHeight) override;

  virtual bool RecvNotifyRegionInvalidated(const nsIntRegion& aRegion) override;
  virtual bool RecvStartFrameTimeRecording(const int32_t& aBufferSize, uint32_t* aOutStartIndex) override;
  virtual bool RecvStopFrameTimeRecording(const uint32_t& aStartIndex, InfallibleTArray<float>* intervals) override;

  // Unused for chrome <-> compositor communication (which this class does).
  // @see CrossProcessCompositorBridgeParent::RecvRequestNotifyAfterRemotePaint
  virtual bool RecvRequestNotifyAfterRemotePaint() override { return true; };

  virtual bool RecvClearVisibleRegions(const uint64_t& aLayersId,
                                       const uint32_t& aPresShellId) override;
  void ClearVisibleRegions(const uint64_t& aLayersId,
                           const Maybe<uint32_t>& aPresShellId);
  virtual bool RecvUpdateVisibleRegion(const VisibilityCounter& aCounter,
                                       const ScrollableLayerGuid& aGuid,
                                       const CSSIntRegion& aRegion) override;
  void UpdateVisibleRegion(const VisibilityCounter& aCounter,
                           const ScrollableLayerGuid& aGuid,
                           const CSSIntRegion& aRegion);

  virtual void ActorDestroy(ActorDestroyReason why) override;

  virtual void ShadowLayersUpdated(LayerTransactionParent* aLayerTree,
                                   const uint64_t& aTransactionId,
                                   const TargetConfig& aTargetConfig,
                                   const InfallibleTArray<PluginWindowData>& aPlugins,
                                   bool aIsFirstPaint,
                                   bool aScheduleComposite,
                                   uint32_t aPaintSequenceNumber,
                                   bool aIsRepeatTransaction,
                                   int32_t aPaintSyncId,
                                   bool aHitTestUpdate) override;
  virtual void ForceComposite(LayerTransactionParent* aLayerTree) override;
  virtual bool SetTestSampleTime(LayerTransactionParent* aLayerTree,
                                 const TimeStamp& aTime) override;
  virtual void LeaveTestMode(LayerTransactionParent* aLayerTree) override;
  virtual void ApplyAsyncProperties(LayerTransactionParent* aLayerTree)
               override;
  virtual void FlushApzRepaints(const LayerTransactionParent* aLayerTree) override;
  virtual void GetAPZTestData(const LayerTransactionParent* aLayerTree,
                              APZTestData* aOutData) override;
  virtual void SetConfirmedTargetAPZC(const LayerTransactionParent* aLayerTree,
                                      const uint64_t& aInputBlockId,
                                      const nsTArray<ScrollableLayerGuid>& aTargets) override;
  virtual AsyncCompositionManager* GetCompositionManager(LayerTransactionParent* aLayerTree) override { return mCompositionManager; }

  virtual PTextureParent* AllocPTextureParent(const SurfaceDescriptor& aSharedData,
                                              const LayersBackend& aLayersBackend,
                                              const TextureFlags& aFlags,
                                              const uint64_t& aId,
                                              const uint64_t& aSerial) override;
  virtual bool DeallocPTextureParent(PTextureParent* actor) override;

  virtual bool IsSameProcess() const override;

  virtual ShmemAllocator* AsShmemAllocator() override { return this; }

  virtual bool AllocShmem(size_t aSize,
                          mozilla::ipc::SharedMemory::SharedMemoryType aType,
                          mozilla::ipc::Shmem* aShmem) override;

  virtual bool AllocUnsafeShmem(size_t aSize,
                                mozilla::ipc::SharedMemory::SharedMemoryType aType,
                                mozilla::ipc::Shmem* aShmem) override;

  virtual void DeallocShmem(mozilla::ipc::Shmem& aShmem) override;

  virtual base::ProcessId GetChildProcessId() override
  {
    return OtherPid();
  }

  virtual void SendAsyncMessage(const InfallibleTArray<AsyncParentMessageData>& aMessage) override;

  virtual CompositorBridgeParentIPCAllocator* AsCompositorBridgeParentIPCAllocator() override { return this; }

  /**
   * Request that the compositor be recreated due to a shared device reset.
   * This must be called on the main thread, and blocks until a task posted
   * to the compositor thread has completed.
   *
   * Note that this posts a task directly, rather than using synchronous
   * IPDL, and waits on a monitor notification from the compositor thread.
   * We do this as a best-effort attempt to jump any IPDL messages that
   * have not yet been posted (and are sitting around in the IO pipe), to
   * minimize the amount of time the main thread is blocked.
   */
  bool ResetCompositor(const nsTArray<LayersBackend>& aBackendHints,
                       TextureFactoryIdentifier* aOutIdentifier);

  /**
   * This forces the is-first-paint flag to true. This is intended to
   * be called by the widget code when it loses its viewport information
   * (or for whatever reason wants to refresh the viewport information).
   * The information refresh happens because the compositor will call
   * SetFirstPaintViewport on the next frame of composition.
   */
  void ForceIsFirstPaint();

  static void SetShadowProperties(Layer* aLayer);

  void NotifyChildCreated(uint64_t aChild);

  void AsyncRender();

  // Can be called from any thread
  void ScheduleRenderOnCompositorThread();
  void SchedulePauseOnCompositorThread();
  void InvalidateOnCompositorThread();
  /**
   * Returns true if a surface was obtained and the resume succeeded; false
   * otherwise.
   */
  bool ScheduleResumeOnCompositorThread();
  bool ScheduleResumeOnCompositorThread(int width, int height);

  virtual void ScheduleComposition();
  void NotifyShadowTreeTransaction(uint64_t aId, bool aIsFirstPaint,
      bool aScheduleComposite, uint32_t aPaintSequenceNumber,
      bool aIsRepeatTransaction, bool aHitTestUpdate);

  /**
   * Check rotation info and schedule a rendering task if needed.
   * Only can be called from compositor thread.
   */
  void ScheduleRotationOnCompositorThread(const TargetConfig& aTargetConfig, bool aIsFirstPaint);

  /**
   * Returns the unique layer tree identifier that corresponds to the root
   * tree of this compositor.
   */
  uint64_t RootLayerTreeId();

  /**
   * Notify local and remote layer trees connected to this compositor that
   * the compositor's local device is being reset. All layers must be
   * invalidated to clear any cached TextureSources.
   *
   * This must be called on the compositor thread.
   */
  void InvalidateRemoteLayers();

  /**
   * Returns a pointer to the CompositorBridgeParent corresponding to the given ID.
   */
  static CompositorBridgeParent* GetCompositorBridgeParent(uint64_t id);

  /**
   * Set aController as the pan/zoom callback for the subtree referred
   * to by aLayersId.
   *
   * Must run on content main thread.
   */
  static void SetControllerForLayerTree(uint64_t aLayersId,
                                        GeckoContentController* aController);

  /**
   * A new child process has been configured to push transactions
   * directly to us.  Transport is to its thread context.
   */
  static PCompositorBridgeParent*
  Create(Transport* aTransport, ProcessId aOtherProcess);

  struct LayerTreeState {
    LayerTreeState();
    ~LayerTreeState();
    RefPtr<Layer> mRoot;
    RefPtr<GeckoContentController> mController;
    CompositorBridgeParent* mParent;
    LayerManagerComposite* mLayerManager;
    // Pointer to the CrossProcessCompositorBridgeParent. Used by APZCs to share
    // their FrameMetrics with the corresponding child process that holds
    // the PCompositorBridgeChild
    CrossProcessCompositorBridgeParent* mCrossProcessParent;
    TargetConfig mTargetConfig;
    APZTestData mApzTestData;
    LayerTransactionParent* mLayerTree;
    nsTArray<PluginWindowData> mPluginData;
    bool mUpdatedPluginDataAvailable;
    RefPtr<CompositorUpdateObserver> mLayerTreeReadyObserver;
    RefPtr<CompositorUpdateObserver> mLayerTreeClearedObserver;

    // Number of times the compositor has been reset without having been
    // acknowledged by the child.
    uint32_t mPendingCompositorUpdates;

    PCompositorBridgeParent* CrossProcessPCompositorBridge() const;
  };

  /**
   * Lookup the indirect shadow tree for |aId| and return it if it
   * exists.  Otherwise null is returned.  This must only be called on
   * the compositor thread.
   */
  static LayerTreeState* GetIndirectShadowTree(uint64_t aId);

#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
  /**
   * Calculates and requests the main thread update plugin positioning, clip,
   * and visibility via ipc.
   */
  bool UpdatePluginWindowState(uint64_t aId);

  /**
   * Plugin visibility helpers for the apz (main thread) and compositor
   * thread.
   */
  void ScheduleShowAllPluginWindows();
  void ScheduleHideAllPluginWindows();
  void ShowAllPluginWindows();
  void HideAllPluginWindows();
#endif

  /**
   * Main thread response for a plugin visibility request made by the
   * compositor thread.
   */
  virtual bool RecvRemotePluginsReady() override;

  /**
   * Used by the profiler to denote when a vsync occured
   */
  static void PostInsertVsyncProfilerMarker(mozilla::TimeStamp aVsyncTimestamp);

  float ComputeRenderIntegrity();

  widget::CompositorWidgetProxy* GetWidgetProxy() { return mWidgetProxy; }

  void ForceComposeToTarget(gfx::DrawTarget* aTarget, const gfx::IntRect* aRect = nullptr);

  bool AsyncPanZoomEnabled() const {
    return !!mApzcTreeManager;
  }

private:
  /**
   * Called during destruction in order to release resources as early as possible.
   */
  void StopAndClearResources();

  /**
   * This returns a reference to the APZCTreeManager to which
   * pan/zoom-related events can be sent.
   */
  static already_AddRefed<APZCTreeManager> GetAPZCTreeManager(uint64_t aLayersId);

  /**
   * Allocate an ID that can be used to refer to a layer tree and
   * associated resources that live only on the compositor thread.
   *
   * Must run on the content main thread.
   */
  static uint64_t AllocateLayerTreeId();
  /**
   * Release compositor-thread resources referred to by |aID|.
   *
   * Must run on the content main thread.
   */
  static void DeallocateLayerTreeId(uint64_t aId);

  static void RequestNotifyLayerTreeReady(uint64_t aLayersId, CompositorUpdateObserver* aObserver);
  static void RequestNotifyLayerTreeCleared(uint64_t aLayersId, CompositorUpdateObserver* aObserver);
  static void SwapLayerTreeObservers(uint64_t aLayer, uint64_t aOtherLayer);

  /**
   * Creates a new RemoteContentController for aTabId. Should only be called on
   * the main thread.
   *
   * aLayersId The layers id for the browser corresponding to aTabId.
   * aContentParent The ContentParent for the process that the TabChild for
   *                aTabId lives in.
   * aBrowserParent The toplevel TabParent for aTabId.
   */
  static bool UpdateRemoteContentController(uint64_t aLayersId,
                                            dom::ContentParent* aContentParent,
                                            const dom::TabId& aTabId,
                                            dom::TabParent* aBrowserParent);

protected:
  // Protected destructor, to discourage deletion outside of Release():
  virtual ~CompositorBridgeParent();

  void DeferredDestroy();

  virtual PLayerTransactionParent*
    AllocPLayerTransactionParent(const nsTArray<LayersBackend>& aBackendHints,
                                 const uint64_t& aId,
                                 TextureFactoryIdentifier* aTextureFactoryIdentifier,
                                 bool* aSuccess) override;
  virtual bool DeallocPLayerTransactionParent(PLayerTransactionParent* aLayers) override;
  virtual void ScheduleTask(already_AddRefed<CancelableRunnable>, int);
  void CompositeToTarget(gfx::DrawTarget* aTarget, const gfx::IntRect* aRect = nullptr);

  void SetEGLSurfaceSize(int width, int height);

  void InitializeLayerManager(const nsTArray<LayersBackend>& aBackendHints);
  void PauseComposition();
  void ResumeComposition();
  void ResumeCompositionAndResize(int width, int height);
  void ForceComposition();
  void CancelCurrentCompositeTask();
  void Invalidate();

  RefPtr<Compositor> NewCompositor(const nsTArray<LayersBackend>& aBackendHints);
  void ResetCompositorTask(const nsTArray<LayersBackend>& aBackendHints,
                           Maybe<TextureFactoryIdentifier>* aOutNewIdentifier);
  Maybe<TextureFactoryIdentifier> ResetCompositorImpl(const nsTArray<LayersBackend>& aBackendHints);

  /**
   * Add a compositor to the global compositor map.
   */
  static void AddCompositor(CompositorBridgeParent* compositor, uint64_t* id);
  /**
   * Remove a compositor from the global compositor map.
   */
  static CompositorBridgeParent* RemoveCompositor(uint64_t id);

  /**
   * Creates the global compositor map.
   */
  static void Initialize();

  /**
   * Destroys the compositor thread and global compositor map.
   */
  static void Shutdown();

  /**
   * Finish the shutdown operation on the compositor thread.
   */
  static void FinishShutdown();

  /**
   * Return true if current state allows compositing, that is
   * finishing a layers transaction.
   */
  bool CanComposite();

  void DidComposite(TimeStamp& aCompositeStart, TimeStamp& aCompositeEnd);

  // The indirect layer tree lock must be held before calling this function.
  // Callback should take (LayerTreeState* aState, const uint64_t& aLayersId)
  template <typename Lambda>
  inline void ForEachIndirectLayerTree(const Lambda& aCallback);

  RefPtr<LayerManagerComposite> mLayerManager;
  RefPtr<Compositor> mCompositor;
  RefPtr<AsyncCompositionManager> mCompositionManager;
  widget::CompositorWidgetProxy* mWidgetProxy;
  TimeStamp mTestTime;
  bool mIsTesting;

  uint64_t mPendingTransaction;

  bool mPaused;

  bool mUseExternalSurfaceSize;
  gfx::IntSize mEGLSurfaceSize;

  mozilla::Monitor mPauseCompositionMonitor;
  mozilla::Monitor mResumeCompositionMonitor;
  mozilla::Monitor mResetCompositorMonitor;

  uint64_t mCompositorID;
  const uint64_t mRootLayerTreeID;

  bool mOverrideComposeReadiness;
  RefPtr<CancelableRunnable> mForceCompositionTask;

  RefPtr<APZCTreeManager> mApzcTreeManager;

  RefPtr<CompositorThreadHolder> mCompositorThreadHolder;
  RefPtr<CompositorVsyncScheduler> mCompositorScheduler;
  // This makes sure the compositorParent is not destroyed before receiving
  // confirmation that the channel is closed.
  // mSelfRef is cleared in DeferredDestroy which is scheduled by ActorDestroy.
  RefPtr<CompositorBridgeParent> mSelfRef;

#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
  // cached plugin data used to reduce the number of updates we request.
  uint64_t mLastPluginUpdateLayerTreeId;
  nsIntPoint mPluginsLayerOffset;
  nsIntRegion mPluginsLayerVisibleRegion;
  nsTArray<PluginWindowData> mCachedPluginData;
  // indicates if plugin window visibility and metric updates are currently
  // being defered due to a scroll operation.
  bool mDeferPluginWindows;
  // indicates if the plugin windows were hidden, and need to be made
  // visible again even if their geometry has not changed.
  bool mPluginWindowsHidden;
#endif

  DISALLOW_EVIL_CONSTRUCTORS(CompositorBridgeParent);
};

} // namespace layers
} // namespace mozilla

#endif // mozilla_layers_CompositorBridgeParent_h