cc: Make OutputSurfaceFrame::sub_buffer_rect optional

content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc

 // Copyright 2014 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/gpu_surfaceless_browser_compositor_output_surface.h"
 
 #include <utility>
 
 #include "cc/output/output_surface_client.h"
 #include "cc/output/output_surface_frame.h"
@@ skipping 55 matching lines @@
   return buffer_queue_->current_texture_id();
 }
 
 void GpuSurfacelessBrowserCompositorOutputSurface::SwapBuffers(
     cc::OutputSurfaceFrame frame) {
   DCHECK(buffer_queue_);
   DCHECK(reshape_size_ == frame.size);
   // TODO(ccameron): What if a swap comes again before OnGpuSwapBuffersCompleted
   // happens, we'd see the wrong swap size there?
   swap_size_ = reshape_size_;
-  buffer_queue_->SwapBuffers(frame.sub_buffer_rect);
+  gfx::Rect damage(swap_size_);
+  if (frame.sub_buffer_rect) {

[danakj, 2017/02/22 00:36:57]

no {} :)

+    damage = *frame.sub_buffer_rect;
+  }
+  buffer_queue_->SwapBuffers(damage);

[danakj, 2017/02/22 00:36:57]

it might be more readable with a ternary

  buffer_queue_->SwapBuffers(frame.sub_buffer_rect ? frame.sub_buffer_rect :
swap_size_);

maybe not tho, wdyt?

[halliwell, 2017/02/22 14:19:28]

I prefer the ternary form, yes.

   GpuBrowserCompositorOutputSurface::SwapBuffers(std::move(frame));
 }
 
 void GpuSurfacelessBrowserCompositorOutputSurface::BindFramebuffer() {
   DCHECK(buffer_queue_);
   buffer_queue_->BindFramebuffer();
 }
 
 GLenum GpuSurfacelessBrowserCompositorOutputSurface::
     GetFramebufferCopyTextureFormat() {
@@ skipping 26 matching lines @@
     force_swap = true;
   }
   buffer_queue_->PageFlipComplete();
   GpuBrowserCompositorOutputSurface::OnGpuSwapBuffersCompleted(
       latency_info, result, params_mac);
   if (force_swap)
     client_->SetNeedsRedrawRect(gfx::Rect(swap_size_));
 }
 
 }  // namespace content