Delay the response to ChildProcessHostMsg_SyncAllocateGpuMemoryBuffer via a callback to allow for b…

content/common/gpu/client/gpu_memory_buffer_impl_shm.h

Index: content/common/gpu/client/gpu_memory_buffer_impl_shm.h
diff --git a/content/common/gpu/client/gpu_memory_buffer_impl_shm.h b/content/common/gpu/client/gpu_memory_buffer_impl_shm.h
index 961ab52d5a08ccf9d6cd1897d9958f24cc81abdd..2ba552c50a2fd6b3781c04e2f35f97648fca136d 100644
--- a/content/common/gpu/client/gpu_memory_buffer_impl_shm.h
+++ b/content/common/gpu/client/gpu_memory_buffer_impl_shm.h
@@ -21,7 +21,7 @@ class GpuMemoryBufferImplShm : public GpuMemoryBufferImpl {
       const gfx::Size& size,
       unsigned internalformat,
       base::ProcessHandle child_process,
-      gfx::GpuMemoryBufferHandle* handle);
+      const AllocationCallback& callback);
 
   static bool IsLayoutSupported(const gfx::Size& size, unsigned internalformat);
   static bool IsUsageSupported(unsigned usage);