Bug 1369840 - Support getting the compositor-side APZ test data over PWebRenderBridge. r=botond

This is fairly straightforward plumbing. The webrender equivalent of PLayerTransaction
is PWebRenderBridge and we can use that to get the compositor-side APZTestData.

MozReview-Commit-ID: JE9WkmejuM9

--HG--
extra : rebase_source : 8872e8dffb988740fa816870cfad25dd6a7d3c21

dom/base/nsDOMWindowUtils.cpp

@@ -3908,13 +3908,20 @@ nsDOMWindowUtils::GetCompositorAPZTestData(JSContext* aContext,
     if (!lm) {
       return NS_OK;
     }
+    APZTestData compositorSideData;
     if (ClientLayerManager* clm = lm->AsClientLayerManager()) {
-      APZTestData compositorSideData;
       clm->GetCompositorSideAPZTestData(&compositorSideData);
-      if (!compositorSideData.ToJS(aOutCompositorTestData, aContext)) {
+    } else if (WebRenderLayerManager* wrlm = lm->AsWebRenderLayerManager()) {
+      if (!wrlm->WrBridge()) {
+        return NS_ERROR_UNEXPECTED;
+      }
+      if (!wrlm->WrBridge()->SendGetAPZTestData(&compositorSideData)) {
         return NS_ERROR_FAILURE;
       }
     }
+    if (!compositorSideData.ToJS(aOutCompositorTestData, aContext)) {
+      return NS_ERROR_FAILURE;
+    }
   }
 
   return NS_OK;

gfx/layers/ipc/PWebRenderBridge.ipdl

@@ -14,6 +14,7 @@ include WebRenderMessages;
 include protocol PCompositorBridge;
 include protocol PTexture;
 
+using mozilla::layers::APZTestData from "mozilla/layers/APZTestData.h";
 using struct mozilla::layers::ScrollableLayerGuid from "FrameMetrics.h";
 using struct mozilla::layers::TextureInfo from "mozilla/layers/CompositorTypes.h";
 using mozilla::layers::CompositableHandle from "mozilla/layers/LayersTypes.h";
@@ -76,6 +77,7 @@ parent:
   sync SetAsyncScrollOffset(ViewID scrollId, float x, float y);
   sync SetAsyncZoom(ViewID scrollId, float zoom);
   async FlushApzRepaints();
+  sync GetAPZTestData() returns (APZTestData data);
 
   async Shutdown();
 child:

gfx/layers/wr/WebRenderBridgeParent.cpp

@@ -768,6 +768,13 @@ WebRenderBridgeParent::RecvFlushApzRepaints()
   return IPC_OK();
 }
 
+mozilla::ipc::IPCResult
+WebRenderBridgeParent::RecvGetAPZTestData(APZTestData* aOutData)
+{
+  mCompositorBridge->GetAPZTestData(GetLayersId(), aOutData);
+  return IPC_OK();
+}
+
 void
 WebRenderBridgeParent::ActorDestroy(ActorDestroyReason aWhy)
 {

gfx/layers/wr/WebRenderBridgeParent.h

@@ -126,6 +126,7 @@ public:
   mozilla::ipc::IPCResult RecvSetAsyncZoom(const FrameMetrics::ViewID& aScrollId,
                                            const float& aZoom) override;
   mozilla::ipc::IPCResult RecvFlushApzRepaints() override;
+  mozilla::ipc::IPCResult RecvGetAPZTestData(APZTestData* data) override;
 
   void ActorDestroy(ActorDestroyReason aWhy) override;
   void SetWebRenderProfilerEnabled(bool aEnabled);