Enable sync allocation of GpuMemoryBuffers from the browser process.

content/common/gpu/client/gpu_memory_buffer_impl_mac.cc

Index: content/common/gpu/client/gpu_memory_buffer_impl_mac.cc
diff --git a/content/common/gpu/client/gpu_memory_buffer_impl_mac.cc b/content/common/gpu/client/gpu_memory_buffer_impl_mac.cc
index 11949c9d6feca8220fc690b6b373f932b1fabf17..3450cd6119e330386af3d2d28ceeab6f71160e93 100644
--- a/content/common/gpu/client/gpu_memory_buffer_impl_mac.cc
+++ b/content/common/gpu/client/gpu_memory_buffer_impl_mac.cc
@@ -10,21 +10,21 @@
 namespace content {
 
 // static
-scoped_ptr<GpuMemoryBufferImpl> GpuMemoryBufferImpl::Create(
-    const gfx::Size& size,
-    unsigned internalformat,
-    unsigned usage) {
+void GpuMemoryBufferImpl::Create(const gfx::Size& size,
+                                 unsigned internalformat,
+                                 unsigned usage,
+                                 const CreationCallback& callback) {
   if (GpuMemoryBufferImplSharedMemory::IsConfigurationSupported(
           size, internalformat, usage)) {
     scoped_ptr<GpuMemoryBufferImplSharedMemory> buffer(
         new GpuMemoryBufferImplSharedMemory(size, internalformat));
-    if (!buffer->Initialize())
-      return scoped_ptr<GpuMemoryBufferImpl>();
-
-    return buffer.PassAs<GpuMemoryBufferImpl>();
+    if (buffer->Initialize()) {
+      callback.Run(buffer.PassAs<GpuMemoryBufferImpl>());
+      return;
+    }
   }
 
-  return scoped_ptr<GpuMemoryBufferImpl>();
+  callback.Run(scoped_ptr<GpuMemoryBufferImpl>());
 }
 
 // static