Fix assorted issues with remote CoreAnimation

content/common/gpu/image_transport_surface_fbo_mac.mm

Index: content/common/gpu/image_transport_surface_fbo_mac.mm
diff --git a/content/common/gpu/image_transport_surface_fbo_mac.mm b/content/common/gpu/image_transport_surface_fbo_mac.mm
index fc7e5ec4bf370933a39cd3ebca0a647539d8b82e..aab15aebbfda88b650e13866221a1936de6eb4aa 100644
--- a/content/common/gpu/image_transport_surface_fbo_mac.mm
+++ b/content/common/gpu/image_transport_surface_fbo_mac.mm
@@ -101,6 +101,8 @@ bool ImageTransportSurfaceFBO::SetBackbufferAllocation(bool allocation) {
     return true;
   backbuffer_suggested_allocation_ = allocation;
   AdjustBufferAllocation();
+  if (!allocation)
+    storage_provider_->DiscardBackbuffer();
   return true;
 }
 
@@ -130,17 +132,15 @@ bool ImageTransportSurfaceFBO::SwapBuffers() {
     return true;
   glFlush();
 
+  DCHECK(!is_swap_buffers_pending_);
+  is_swap_buffers_pending_ = true;
+
   GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params params;
-  params.surface_handle = storage_provider_->GetSurfaceHandle();
+  params.surface_handle = storage_provider_->SwapBuffersAndGetSurfaceHandle();
   params.size = GetSize();
   params.scale_factor = scale_factor_;
   params.latency_info.swap(latency_info_);
   helper_->SendAcceleratedSurfaceBuffersSwapped(params);
-
-  DCHECK(!is_swap_buffers_pending_);
-  is_swap_buffers_pending_ = true;
-
-  storage_provider_->WillSwapBuffers();
   return true;
 }