Enable sync allocation of GpuMemoryBuffers from the browser process.

content/browser/gpu/browser_gpu_channel_host_factory.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/gpu/browser_gpu_channel_host_factory.h"
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/thread_restrictions.h"
@@ skipping 474 matching lines @@
 // static
 void BrowserGpuChannelHostFactory::AllocateGpuMemoryBufferOnIO(
     AllocateGpuMemoryBufferRequest* request) {
   if (!GpuMemoryBufferImpl::IsFormatValid(request->internalformat) ||
       !GpuMemoryBufferImpl::IsUsageValid(request->usage)) {
     request->result = scoped_ptr<gfx::GpuMemoryBuffer>();
     request->event.Signal();
     return;
   }
 
-  request->result = GpuMemoryBufferImpl::Create(
-                        gfx::Size(request->width, request->height),
-                        request->internalformat,
-                        request->usage).PassAs<gfx::GpuMemoryBuffer>();
-  request->event.Signal();
+  GpuMemoryBufferImpl::Create(
+      gfx::Size(request->width, request->height),
+      request->internalformat,
+      request->usage,
+      base::Bind(&BrowserGpuChannelHostFactory::GpuMemoryBufferImplCreatedOnIO,
+                 base::Unretained(request)));
 }
 
 // static
 void BrowserGpuChannelHostFactory::DeleteGpuMemoryBufferOnIO(
     scoped_ptr<gfx::GpuMemoryBuffer> buffer) {
 }
 
+// static
+void BrowserGpuChannelHostFactory::GpuMemoryBufferImplCreatedOnIO(

[reveman, 2014/09/09 17:18:26]

I think this should be named "OnGpuMemoryBufferCreated" or
"OnGpuMemoryBufferAllocated". There's obviously a conflict if using "Created"
which I think we need to address no matter what. It's getting pretty confusing
to have this class implement both the GpuMemoryBuffer part of
GpuChannelHostFactory and GpuMemoryBufferFactoryHost. How about we move the
GpuMemoryBufferFactoryHost part out into a GpuMemoryBufferFactoryHostImpl class?

[alexst (slow to review), 2014/09/09 21:53:57]

Yeah, the namespace is getting crowded, I'll add GpuMemoryBufferFactoryHostImpl.

+    AllocateGpuMemoryBufferRequest* request,
+    scoped_ptr<GpuMemoryBufferImpl> buffer) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));

[reveman, 2014/09/09 17:18:26]

nit: blank line after this DCHECK to be consistent in style with other
GpuMemoryBuffer related functions.

[alexst (slow to review), 2014/09/09 21:53:56]

Done.

+  request->result = buffer.PassAs<gfx::GpuMemoryBuffer>();
+  request->event.Signal();
+}
+
 void BrowserGpuChannelHostFactory::OnGpuMemoryBufferCreated(
     uint32 request_id,
     const gfx::GpuMemoryBufferHandle& handle) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   CreateGpuMemoryBufferCallbackMap::iterator iter =
       create_gpu_memory_buffer_requests_.find(request_id);
   DCHECK(iter != create_gpu_memory_buffer_requests_.end());
   iter->second.Run(handle);
   create_gpu_memory_buffer_requests_.erase(iter);
 }
 
 }  // namespace content