Bug 1517328 - Make APZCTreeManager::FlushApzRepaints() static. r=kats

Since we no longer throttle paints, this function just sends a notification,
which does not rely on any tree manager state.

Depends on D15592

Differential Revision: https://phabricator.services.mozilla.com/D15593

--HG--
extra : moz-landing-system : lando

gfx/layers/apz/src/APZCTreeManager.cpp

@@ -1123,7 +1123,7 @@ static bool WillHandleInput(const PanGestureOrScrollWheelInput& aPanInput) {
   return APZInputBridge::ActionForWheelEvent(&wheelEvent).isSome();
 }
 
-void APZCTreeManager::FlushApzRepaints(LayersId aLayersId) {
+/*static*/ void APZCTreeManager::FlushApzRepaints(LayersId aLayersId) {
   // Previously, paints were throttled and therefore this method was used to
   // ensure any pending paints were flushed. Now, paints are flushed
   // immediately, so it is safe to simply send a notification now.

gfx/layers/apz/src/APZCTreeManager.h

@@ -222,13 +222,6 @@ class APZCTreeManager : public IAPZCTreeManager, public APZInputBridge {
   void SampleForWebRender(wr::TransactionWrapper& aTxn,
                           const TimeStamp& aSampleTime);
 
-  /**
-   * Walk the tree of APZCs and flushes the repaint requests for all the APZCS
-   * corresponding to the given layers id. Finally, sends a flush complete
-   * notification to the GeckoContentController for the layers id.
-   */
-  void FlushApzRepaints(LayersId aLayersId);
-
   /**
    * General handler for incoming input events. Manipulates the frame metrics
    * based on what type of input it is. For example, a PinchGestureEvent will
@@ -536,6 +529,12 @@ class APZCTreeManager : public IAPZCTreeManager, public APZInputBridge {
       const ScrollbarData& aScrollbarData, bool aScrollbarIsDescendant,
       AsyncTransformComponentMatrix* aOutClipTransform);
 
+  /**
+   * Dispatch a flush complete notification from the repaint thread of the
+   * content controller for the given layers id.
+   */
+  static void FlushApzRepaints(LayersId aLayersId);
+
   // Assert that the current thread is the sampler thread for this APZCTM.
   void AssertOnSamplerThread();
   // Assert that the current thread is the updater thread for this APZCTM.

gfx/layers/ipc/CompositorBridgeParent.cpp

@@ -1352,15 +1352,12 @@ void CompositorBridgeParent::SetTestAsyncZoom(
 }
 
 void CompositorBridgeParent::FlushApzRepaints(const LayersId& aLayersId) {
-  MOZ_ASSERT(mApzcTreeManager);
   MOZ_ASSERT(mApzUpdater);
   MOZ_ASSERT(aLayersId.IsValid());
-  RefPtr<CompositorBridgeParent> self = this;
   mApzUpdater->RunOnControllerThread(
       aLayersId, NS_NewRunnableFunction(
-                     "layers::CompositorBridgeParent::FlushApzRepaints", [=]() {
-                       self->mApzcTreeManager->FlushApzRepaints(aLayersId);
-                     }));
+                     "layers::CompositorBridgeParent::FlushApzRepaints",
+                     [=]() { APZCTreeManager::FlushApzRepaints(aLayersId); }));
 }
 
 void CompositorBridgeParent::GetAPZTestData(const LayersId& aLayersId,