Partial swap implementation for surfaceless

content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc

Index: content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc
diff --git a/content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc b/content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc
index a1e7f54a117e103294fa4a0217e1d53a4983b881..e73ff67601b01077cbc346e4f75c0cff0a417adb 100644
--- a/content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc
+++ b/content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc
@@ -38,6 +38,11 @@ void GpuSurfacelessBrowserCompositorOutputSurface::SwapBuffers(
     cc::CompositorFrame* frame) {
   DCHECK(output_surface_);
 
+  output_surface_->SwapBuffers(frame->gl_frame_data->sub_buffer_rect);
+  // Disable the sub-buffer processing path on the parent classes, because we
+  // have handled it here.
+  frame->gl_frame_data->sub_buffer_rect = gfx::Rect(frame->gl_frame_data->size);

[alexst (slow to review), 2014/09/18 15:39:15]

We have a reflector, which is used for multimon mirroring that copies these as
well. It needs the damage rect too.

I think we can remove this here and implement virtual PostSubBuffer(..) in the
GPU process surface to ignore the rect.

[achaulk, 2014/09/18 16:45:02]

Done.

+
   const gfx::Size& size = frame->gl_frame_data->size;
   context_provider_->ContextGL()->ScheduleOverlayPlaneCHROMIUM(
       0,
@@ -51,7 +56,6 @@ void GpuSurfacelessBrowserCompositorOutputSurface::SwapBuffers(
       0,
       1.0f,
       1.0f);
-  output_surface_->SwapBuffers();
   GpuBrowserCompositorOutputSurface::SwapBuffers(frame);
 }