gpu: Remove Echo and SwapCompletion GL interfacess

gpu/command_buffer/client/gles2_implementation.cc

Index: gpu/command_buffer/client/gles2_implementation.cc
diff --git a/gpu/command_buffer/client/gles2_implementation.cc b/gpu/command_buffer/client/gles2_implementation.cc
index 852410b7e156bf5324edf3840a6e17d2199cafc5..88e27de91ff336e185602f0a40ae0a232a12605b 100644
--- a/gpu/command_buffer/client/gles2_implementation.cc
+++ b/gpu/command_buffer/client/gles2_implementation.cc
@@ -2849,23 +2849,11 @@ void GLES2Implementation::GetVertexAttribiv(
 
 void GLES2Implementation::Swap() {
   SwapBuffers();
-  gpu_control_->Echo(
-      base::Bind(&GLES2Implementation::OnSwapBuffersComplete,
-                 weak_ptr_factory_.GetWeakPtr()));
 }
 
 void GLES2Implementation::PartialSwapBuffers(const gfx::Rect& sub_buffer) {
-  PostSubBufferCHROMIUM(sub_buffer.x(),
-                        sub_buffer.y(),
-                        sub_buffer.width(),
-                        sub_buffer.height());
-  gpu_control_->Echo(base::Bind(&GLES2Implementation::OnSwapBuffersComplete,
-                                weak_ptr_factory_.GetWeakPtr()));
-}
-
-void GLES2Implementation::SetSwapBuffersCompleteCallback(
-      const base::Closure& swap_buffers_complete_callback) {
-  swap_buffers_complete_callback_ = swap_buffers_complete_callback;
+  PostSubBufferCHROMIUM(
+      sub_buffer.x(), sub_buffer.y(), sub_buffer.width(), sub_buffer.height());
 }
 
 static GLenum GetGLESOverlayTransform(gfx::OverlayTransform plane_transform) {
@@ -2908,11 +2896,6 @@ void GLES2Implementation::ScheduleOverlayPlane(
                                uv_rect.height());
 }
 
-void GLES2Implementation::OnSwapBuffersComplete() {
-  if (!swap_buffers_complete_callback_.is_null())
-    swap_buffers_complete_callback_.Run();
-}
-
 GLboolean GLES2Implementation::EnableFeatureCHROMIUM(
     const char* feature) {
   GPU_CLIENT_SINGLE_THREAD_CHECK();