Bug 966679 - Resolve RefLayers during IPDL transactions. r=nical

gfx/layers/composite/AsyncCompositionManager.cpp

@@ -98,6 +98,9 @@ WalkTheTree(Layer* aLayer,
 void
 AsyncCompositionManager::ResolveRefLayers()
 {
+  if (!mLayerManager->GetRoot()) {
+    return;
+  }
   WalkTheTree<Resolve>(mLayerManager->GetRoot(),
                        mReadyForCompose,
                        mTargetConfig);
@@ -106,6 +109,9 @@ AsyncCompositionManager::ResolveRefLayers()
 void
 AsyncCompositionManager::DetachRefLayers()
 {
+  if (!mLayerManager->GetRoot()) {
+    return;
+  }
   WalkTheTree<Detach>(mLayerManager->GetRoot(),
                       mReadyForCompose,
                       mTargetConfig);

gfx/layers/composite/AsyncCompositionManager.h

@@ -201,10 +201,18 @@ private:
 class MOZ_STACK_CLASS AutoResolveRefLayers {
 public:
   AutoResolveRefLayers(AsyncCompositionManager* aManager) : mManager(aManager)
-  { mManager->ResolveRefLayers(); }
+  {
+    if (mManager) {
+      mManager->ResolveRefLayers();
+    }
+  }
 
   ~AutoResolveRefLayers()
-  { mManager->DetachRefLayers(); }
+  {
+    if (mManager) {
+      mManager->DetachRefLayers();
+    }
+  }
 
 private:
   AsyncCompositionManager* mManager;

gfx/layers/ipc/CompositorParent.h

@@ -100,6 +100,7 @@ public:
                                    const TargetConfig& aTargetConfig,
                                    bool aIsFirstPaint,
                                    bool aScheduleComposite) MOZ_OVERRIDE;
+  virtual AsyncCompositionManager* GetCompositionManager() MOZ_OVERRIDE { return mCompositionManager; }
   /**
    * 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

gfx/layers/ipc/LayerTransactionParent.cpp

@@ -40,6 +40,7 @@
 #include "nsTraceRefcnt.h"              // for MOZ_COUNT_CTOR, etc
 #include "GeckoProfiler.h"
 #include "mozilla/layers/TextureHost.h"
+#include "mozilla/layers/AsyncCompositionManager.h"
 
 typedef std::vector<mozilla::layers::EditReply> EditReplyVector;
 
@@ -205,7 +206,10 @@ LayerTransactionParent::RecvUpdate(const InfallibleTArray<Edit>& cset,
 
   EditReplyVector replyv;
 
-  layer_manager()->BeginTransactionWithDrawTarget(nullptr);
+  {
+    AutoResolveRefLayers resolve(mShadowLayersManager->GetCompositionManager());
+    layer_manager()->BeginTransaction();
+  }
 
   for (EditArray::index_type i = 0; i < cset.Length(); ++i) {
     const Edit& edit = cset[i];
@@ -439,7 +443,10 @@ LayerTransactionParent::RecvUpdate(const InfallibleTArray<Edit>& cset,
     }
   }
 
-  layer_manager()->EndTransaction(nullptr, nullptr, LayerManager::END_NO_IMMEDIATE_REDRAW);
+  {
+    AutoResolveRefLayers resolve(mShadowLayersManager->GetCompositionManager());
+    layer_manager()->EndTransaction(nullptr, nullptr, LayerManager::END_NO_IMMEDIATE_REDRAW);
+  }
 
   if (reply) {
     reply->SetCapacity(replyv.size());

gfx/layers/ipc/ShadowLayersManager.h

@@ -12,6 +12,7 @@ namespace layers {
 
 class TargetConfig;
 class LayerTransactionParent;
+class AsyncCompositionManager;
 
 class ShadowLayersManager
 {
@@ -20,6 +21,8 @@ public:
                                      const TargetConfig& aTargetConfig,
                                      bool aIsFirstPaint,
                                      bool aScheduleComposite) = 0;
+
+    virtual AsyncCompositionManager* GetCompositionManager() { return nullptr; }
 };
 
 } // layers