Bug 1445662 - Update RemoteContentController to allow the GPU process controller thread to be different from the compositor thread. r=rhunt

A couple of RemoteContentController methods get called on the controller
thread in the GPU process. This is the same as the compositor thread so
we could just do compositor-thread stuff here, but we will want to
support the controller thread being the main thread instead of the
compositor thread. So we detect those cases and bounce the message
accordingly.

gfx/layers/ipc/RemoteContentController.cpp

@@ -59,6 +59,25 @@ RemoteContentController::HandleTapOnMainThread(TapType aTapType,
   }
 }
 
+void
+RemoteContentController::HandleTapOnCompositorThread(TapType aTapType,
+                                                     LayoutDevicePoint aPoint,
+                                                     Modifiers aModifiers,
+                                                     ScrollableLayerGuid aGuid,
+                                                     uint64_t aInputBlockId)
+{
+  MOZ_ASSERT(XRE_IsGPUProcess());
+  MOZ_ASSERT(MessageLoop::current() == mCompositorThread);
+
+  // The raw pointer to APZCTreeManagerParent is ok here because we are on the
+  // compositor thread.
+  APZCTreeManagerParent* apzctmp =
+      CompositorBridgeParent::GetApzcTreeManagerParentForRoot(aGuid.mLayersId);
+  if (apzctmp) {
+    Unused << apzctmp->SendHandleTap(aTapType, aPoint, aModifiers, aGuid, aInputBlockId);
+  }
+}
+
 void
 RemoteContentController::HandleTap(TapType aTapType,
                                    const LayoutDevicePoint& aPoint,
@@ -69,16 +88,24 @@ RemoteContentController::HandleTap(TapType aTapType,
   APZThreadUtils::AssertOnControllerThread();
 
   if (XRE_GetProcessType() == GeckoProcessType_GPU) {
-    MOZ_ASSERT(MessageLoop::current() == mCompositorThread);
-
-    // The raw pointer to APZCTreeManagerParent is ok here because we are on the
-    // compositor thread.
-    APZCTreeManagerParent* apzctmp =
-        CompositorBridgeParent::GetApzcTreeManagerParentForRoot(aGuid.mLayersId);
-    if (apzctmp) {
-      Unused << apzctmp->SendHandleTap(aTapType, aPoint, aModifiers, aGuid, aInputBlockId);
+    if (MessageLoop::current() == mCompositorThread) {
+      HandleTapOnCompositorThread(aTapType, aPoint, aModifiers, aGuid, aInputBlockId);
+    } else {
+      // We have to send messages from the compositor thread
+      mCompositorThread->PostTask(NewRunnableMethod<TapType,
+                                                    LayoutDevicePoint,
+                                                    Modifiers,
+                                                    ScrollableLayerGuid,
+                                                    uint64_t>(
+        "layers::RemoteContentController::HandleTapOnCompositorThread",
+        this,
+        &RemoteContentController::HandleTapOnCompositorThread,
+        aTapType,
+        aPoint,
+        aModifiers,
+        aGuid,
+        aInputBlockId));
     }
-
     return;
   }
 
@@ -105,6 +132,24 @@ RemoteContentController::HandleTap(TapType aTapType,
   }
 }
 
+void
+RemoteContentController::NotifyPinchGestureOnCompositorThread(
+    PinchGestureInput::PinchGestureType aType,
+    const ScrollableLayerGuid& aGuid,
+    LayoutDeviceCoord aSpanChange,
+    Modifiers aModifiers)
+{
+  MOZ_ASSERT(MessageLoop::current() == mCompositorThread);
+
+  // The raw pointer to APZCTreeManagerParent is ok here because we are on the
+  // compositor thread.
+  APZCTreeManagerParent* apzctmp =
+      CompositorBridgeParent::GetApzcTreeManagerParentForRoot(aGuid.mLayersId);
+  if (apzctmp) {
+    Unused << apzctmp->SendNotifyPinchGesture(aType, aGuid, aSpanChange, aModifiers);
+  }
+}
+
 void
 RemoteContentController::NotifyPinchGesture(PinchGestureInput::PinchGestureType aType,
                                             const ScrollableLayerGuid& aGuid,
@@ -119,16 +164,22 @@ RemoteContentController::NotifyPinchGesture(PinchGestureInput::PinchGestureType
   // If we're in the GPU process, try to find a handle to the parent process
   // and send it there.
   if (XRE_IsGPUProcess()) {
-    MOZ_ASSERT(MessageLoop::current() == mCompositorThread);
-
-    // The raw pointer to APZCTreeManagerParent is ok here because we are on the
-    // compositor thread.
-    APZCTreeManagerParent* apzctmp =
-        CompositorBridgeParent::GetApzcTreeManagerParentForRoot(aGuid.mLayersId);
-    if (apzctmp) {
-      Unused << apzctmp->SendNotifyPinchGesture(aType, aGuid, aSpanChange, aModifiers);
-      return;
+    if (MessageLoop::current() == mCompositorThread) {
+      NotifyPinchGestureOnCompositorThread(aType, aGuid, aSpanChange, aModifiers);
+    } else {
+      mCompositorThread->PostTask(NewRunnableMethod<PinchGestureInput::PinchGestureType,
+                                                    ScrollableLayerGuid,
+                                                    LayoutDeviceCoord,
+                                                    Modifiers>(
+        "layers::RemoteContentController::NotifyPinchGestureOnCompositorThread",
+        this,
+        &RemoteContentController::NotifyPinchGestureOnCompositorThread,
+        aType,
+        aGuid,
+        aSpanChange,
+        aModifiers));
     }
+    return;
   }
 
   // If we're in the parent process, handle it directly. We don't have a handle

gfx/layers/ipc/RemoteContentController.h

@@ -90,6 +90,15 @@ private:
                              Modifiers aModifiers,
                              ScrollableLayerGuid aGuid,
                              uint64_t aInputBlockId);
+  void HandleTapOnCompositorThread(TapType aType,
+                                   LayoutDevicePoint aPoint,
+                                   Modifiers aModifiers,
+                                   ScrollableLayerGuid aGuid,
+                                   uint64_t aInputBlockId);
+  void NotifyPinchGestureOnCompositorThread(PinchGestureInput::PinchGestureType aType,
+                                            const ScrollableLayerGuid& aGuid,
+                                            LayoutDeviceCoord aSpanChange,
+                                            Modifiers aModifiers);
 
   void CancelAutoscrollInProcess(const ScrollableLayerGuid& aScrollId);
   void CancelAutoscrollCrossProcess(const ScrollableLayerGuid& aScrollId);