Make CommandBuffer::Flush asynchronous, and add CommandBuffer::FlushSync with former semantics.

chrome/plugin/command_buffer_stub.cc

Index: chrome/plugin/command_buffer_stub.cc
diff --git a/chrome/plugin/command_buffer_stub.cc b/chrome/plugin/command_buffer_stub.cc
index de9bbdb16e28382b8ae2296a40cd40fe50667fff..2ef657a7503b97c6875660a935aba4380577fed2 100644
--- a/chrome/plugin/command_buffer_stub.cc
+++ b/chrome/plugin/command_buffer_stub.cc
@@ -140,11 +140,11 @@ void CommandBufferStub::OnAsyncGetState() {
 
 void CommandBufferStub::OnFlush(int32 put_offset,
                                 gpu::CommandBuffer::State* state) {
-  *state = command_buffer_->Flush(put_offset);
+  *state = command_buffer_->FlushSync(put_offset);
 }
 
 void CommandBufferStub::OnAsyncFlush(int32 put_offset) {
-  gpu::CommandBuffer::State state = command_buffer_->Flush(put_offset);
+  gpu::CommandBuffer::State state = command_buffer_->FlushSync(put_offset);
   Send(new GpuCommandBufferMsg_UpdateState(route_id_, state));
 }