Avoid sending duplicate flushes

The duplicate flush after the swapbuffers makes handling commands from other stubs difficult, so get rid of it.

BUG=112349
TEST=


Review URL: http://codereview.chromium.org/9567026

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@124604 0039d316-1c4b-4281-b951-d872f2087c98

content/common/gpu/client/command_buffer_proxy.cc

@@ -27,7 +27,8 @@ CommandBufferProxy::CommandBufferProxy(
     int route_id)
     : channel_(channel),
       route_id_(route_id),
-      flush_count_(0) {
+      flush_count_(0),
+      last_put_offset_(-1) {
 }
 
 CommandBufferProxy::~CommandBufferProxy() {
@@ -171,6 +172,11 @@ void CommandBufferProxy::Flush(int32 put_offset) {
 
   TRACE_EVENT1("gpu", "CommandBufferProxy::Flush", "put_offset", put_offset);
 
+  if (last_put_offset_ == put_offset)
+    return;
+
+  last_put_offset_ = put_offset;
+
   Send(new GpuCommandBufferMsg_AsyncFlush(route_id_,
                                           put_offset,
                                           ++flush_count_));
@@ -201,6 +207,7 @@ void CommandBufferProxy::SetGetBuffer(int32 shm_id) {
     return;
 
   Send(new GpuCommandBufferMsg_SetGetBuffer(route_id_, shm_id));
+  last_put_offset_ = -1;
 }
 
 void CommandBufferProxy::SetGetOffset(int32 get_offset) {

content/common/gpu/client/command_buffer_proxy.h

@@ -148,6 +148,7 @@ class CommandBufferProxy : public gpu::CommandBuffer,
   GpuChannelHost* channel_;
   int route_id_;
   unsigned int flush_count_;
+  int32 last_put_offset_;
 
   // Tasks to be invoked in echo responses.
   std::queue<base::Closure> echo_tasks_;