Bug 1101974. Part 1: Create VsyncDispatcher at nsBaseWidget. r=roc

widget/nsBaseWidget.cpp

@@ -43,6 +43,7 @@
 #include "mozilla/MouseEvents.h"
 #include "GLConsts.h"
 #include "mozilla/unused.h"
+#include "mozilla/VsyncDispatcher.h"
 #include "mozilla/layers/APZCTreeManager.h"
 #include "mozilla/layers/ChromeProcessController.h"
 
@@ -111,6 +112,7 @@ nsBaseWidget::nsBaseWidget()
 : mWidgetListener(nullptr)
 , mAttachedWidgetListener(nullptr)
 , mContext(nullptr)
+, mVsyncDispatcher(nullptr)
 , mCursor(eCursor_standard)
 , mUpdateCursor(true)
 , mBorderStyle(eBorderStyle_none)
@@ -229,8 +231,12 @@ nsBaseWidget::~nsBaseWidget()
 
   NS_IF_RELEASE(mContext);
   delete mOriginalBounds;
-}
 
+  // Can have base widgets that are things like tooltips which don't have vsyncDispatchers
+  if (mVsyncDispatcher) {
+    mVsyncDispatcher->Shutdown();
+  }
+}
 
 //-------------------------------------------------------------------------
 //
@@ -944,6 +950,24 @@ nsBaseWidget::GetPreferredCompositorBackends(nsTArray<LayersBackend>& aHints)
   aHints.AppendElement(LayersBackend::LAYERS_BASIC);
 }
 
+void nsBaseWidget::CreateVsyncDispatcher()
+{
+  if (gfxPrefs::HardwareVsyncEnabled()) {
+    // Parent directly listens to the vsync source whereas
+    // child process communicate via IPC
+    // Should be called AFTER gfxPlatform is initialized
+    if (XRE_IsParentProcess()) {
+      mVsyncDispatcher = new VsyncDispatcher();
+    }
+  }
+}
+
+VsyncDispatcher*
+nsBaseWidget::GetVsyncDispatcher()
+{
+  return mVsyncDispatcher;
+}
+
 void nsBaseWidget::CreateCompositor(int aWidth, int aHeight)
 {
   // This makes sure that gfxPlatforms gets initialized if it hasn't by now.
@@ -961,6 +985,7 @@ void nsBaseWidget::CreateCompositor(int aWidth, int aHeight)
     return;
   }
 
+  CreateVsyncDispatcher();
   mCompositorParent = NewCompositorParent(aWidth, aHeight);
   MessageChannel *parentChannel = mCompositorParent->GetIPCChannel();
   nsRefPtr<ClientLayerManager> lm = new ClientLayerManager(this);

widget/nsBaseWidget.h

@@ -37,6 +37,8 @@ class CompositorParent;
 class APZCTreeManager;
 class GeckoContentController;
 }
+
+class VsyncDispatcher;
 }
 
 namespace base {
@@ -138,6 +140,8 @@ public:
                                           LayerManagerPersistence aPersistence = LAYER_MANAGER_CURRENT,
                                           bool* aAllowRetaining = nullptr);
 
+  VsyncDispatcher*        GetVsyncDispatcher() MOZ_OVERRIDE;
+  virtual void            CreateVsyncDispatcher();
   virtual CompositorParent* NewCompositorParent(int aSurfaceWidth, int aSurfaceHeight);
   virtual void            CreateCompositor();
   virtual void            CreateCompositor(int aWidth, int aHeight);
@@ -414,6 +418,7 @@ protected:
   nsRefPtr<LayerManager> mBasicLayerManager;
   nsRefPtr<CompositorChild> mCompositorChild;
   nsRefPtr<CompositorParent> mCompositorParent;
+  nsRefPtr<mozilla::VsyncDispatcher> mVsyncDispatcher;
   nsRefPtr<APZCTreeManager> mAPZC;
   nsRefPtr<WidgetShutdownObserver> mShutdownObserver;
   nsCursor          mCursor;

widget/nsIWidget.h

@@ -36,6 +36,7 @@ class   nsIntRegion;
 class   nsIScreen;
 
 namespace mozilla {
+class VsyncDispatcher;
 namespace dom {
 class TabChild;
 }
@@ -691,6 +692,7 @@ class nsIWidget : public nsISupports {
     typedef mozilla::widget::InputContext InputContext;
     typedef mozilla::widget::InputContextAction InputContextAction;
     typedef mozilla::widget::SizeConstraints SizeConstraints;
+    typedef mozilla::VsyncDispatcher VsyncDispatcher;
 
     // Used in UpdateThemeGeometries.
     struct ThemeGeometry {
@@ -869,6 +871,11 @@ class nsIWidget : public nsISupports {
      */
     virtual float GetDPI() = 0;
 
+    /**
+     * Returns the VsyncDispatcher associated with this widget
+     */
+    virtual VsyncDispatcher* GetVsyncDispatcher() = 0;
+
     /**
      * Return the default scale factor for the window. This is the
      * default number of device pixels per CSS pixel to use. This should