Only add rescheduled message when there are commands to reschedule.

Adding this message all the time prevents us from processing other command buffers when there really isn't anything left to do.

BUG=112349
TEST=


Review URL: http://codereview.chromium.org/9583021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@124759 0039d316-1c4b-4281-b951-d872f2087c98

content/common/gpu/gpu_channel.cc

@@ -260,7 +260,7 @@ void GpuChannel::HandleMessage() {
       // buffer that became unscheduled.
       GpuCommandBufferStub* stub = stubs_.Lookup(message->routing_id());
       if (stub) {
-        if (!stub->IsScheduled() || stub->HasMoreWork()) {
+        if (stub->HasUnprocessedCommands() || stub->HasMoreWork()) {
           deferred_messages_.push_front(new GpuCommandBufferMsg_Rescheduled(
               stub->route_id()));
         }

content/common/gpu/gpu_command_buffer_stub.cc

@@ -142,6 +142,14 @@ bool GpuCommandBufferStub::HasMoreWork() {
   return scheduler_.get() && scheduler_->HasMoreWork();
 }
 
+bool GpuCommandBufferStub::HasUnprocessedCommands() {
+  if (command_buffer_.get()) {
+    gpu::CommandBuffer::State state = command_buffer_->GetLastState();
+    return state.put_offset != state.get_offset;
+  }
+  return false;
+}
+
 void GpuCommandBufferStub::OnEcho(const IPC::Message& message) {
   TRACE_EVENT0("gpu", "GpuCommandBufferStub::OnEcho");
   Send(new IPC::Message(message));

content/common/gpu/gpu_command_buffer_stub.h

@@ -129,6 +129,9 @@ class GpuCommandBufferStub
   // Whether this command buffer needs to be polled again in the future.
   bool HasMoreWork();
 
+  // Whether there are commands in the buffer that haven't been processed.
+  bool HasUnprocessedCommands();
+
   gpu::gles2::GLES2Decoder* decoder() const { return decoder_.get(); }
   gpu::GpuScheduler* scheduler() const { return scheduler_.get(); }