cc: Make OutputSurfaceFrame::sub_buffer_rect optional

content/browser/compositor/offscreen_browser_compositor_output_surface.cc

 // Copyright 2015 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/compositor/offscreen_browser_compositor_output_surface.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "build/build_config.h"
@@ skipping 118 matching lines @@
   if (need_to_bind) {
     GLES2Interface* gl = context_provider_->ContextGL();
     gl->BindFramebuffer(GL_FRAMEBUFFER, fbo_);
   }
 }
 
 void OffscreenBrowserCompositorOutputSurface::SwapBuffers(
     cc::OutputSurfaceFrame frame) {
   gfx::Size surface_size = frame.size;
   DCHECK(surface_size == reshape_size_);
-  gfx::Rect swap_rect = frame.sub_buffer_rect;
 
   if (reflector_) {
-    if (swap_rect == gfx::Rect(surface_size))
+    if (frame.sub_buffer_rect)
+      reflector_->OnSourcePostSubBuffer(*frame.sub_buffer_rect, surface_size);
+    else
       reflector_->OnSourceSwapBuffers(surface_size);
-    else
-      reflector_->OnSourcePostSubBuffer(swap_rect, surface_size);
   }
 
   // TODO(oshima): sync with the reflector's SwapBuffersComplete
   // (crbug.com/520567).
   // The original implementation had a flickering issue (crbug.com/515332).
   gpu::gles2::GLES2Interface* gl = context_provider_->ContextGL();
   const GLuint64 fence_sync = gl->InsertFenceSyncCHROMIUM();
   gl->ShallowFlushCHROMIUM();
 
   gpu::SyncToken sync_token;
@@ skipping 31 matching lines @@
   }
 }
 
 void OffscreenBrowserCompositorOutputSurface::OnSwapBuffersComplete(
     const std::vector<ui::LatencyInfo>& latency_info) {
   RenderWidgetHostImpl::CompositorFrameDrawn(latency_info);
   client_->DidReceiveSwapBuffersAck();
 }
 
 }  // namespace content