Bug 933082 - Part 2: propagate the mIPCOpen flag, avoid crashing in DestroySharedSurface on a dead channel - r=nical

gfx/layers/ipc/ISurfaceAllocator.cpp

@@ -127,6 +127,9 @@ ISurfaceAllocator::DestroySharedSurface(SurfaceDescriptor* aSurface)
   if (!aSurface) {
     return;
   }
+  if (!IPCOpen()) {
+    return;
+  }
   if (PlatformDestroySharedSurface(aSurface)) {
     return;
   }

gfx/layers/ipc/ISurfaceAllocator.h

@@ -124,6 +124,8 @@ ISurfaceAllocator() {}
     return nullptr;
   }
 
+  virtual bool IPCOpen() const { return true; }
+
   // Returns true if aSurface wraps a Shmem.
   static bool IsShmem(SurfaceDescriptor* aSurface);
 

gfx/layers/ipc/ShadowLayers.cpp

@@ -617,6 +617,12 @@ ShadowLayerForwarder::DeallocShmem(ipc::Shmem& aShmem)
   mShadowManager->DeallocShmem(aShmem);
 }
 
+bool
+ShadowLayerForwarder::IPCOpen() const
+{
+  return mShadowManager->IPCOpen();
+}
+
 /*static*/ already_AddRefed<gfxASurface>
 ShadowLayerForwarder::OpenDescriptor(OpenMode aMode,
                                      const SurfaceDescriptor& aSurface)

gfx/layers/ipc/ShadowLayers.h

@@ -394,6 +394,8 @@ public:
                           mozilla::ipc::Shmem* aShmem) MOZ_OVERRIDE;
   virtual void DeallocShmem(mozilla::ipc::Shmem& aShmem) MOZ_OVERRIDE;
 
+  virtual bool IPCOpen() const MOZ_OVERRIDE;
+
   /**
    * Construct a shadow of |aLayer| on the "other side", at the
    * LayerManagerComposite.