exo: Send damage to compositor when committing new buffer.

components/exo/wayland/clients/motion_events.cc

 // Copyright 2016 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.
 
 // Implementation of a client that produces output in the form of RGBA
 // buffers when receiving pointer/touch events. RGB contains the lower
 // 24 bits of the event timestamp and A is 0xff.
 
 #include <fcntl.h>
 #include <linux-dmabuf-unstable-v1-client-protocol.h>
@@ skipping 655 matching lines @@
         ++frames;
         benchmark_wall_time += base::TimeTicks::Now() - wall_time_start;
         benchmark_cpu_time += base::ThreadTicks::Now() - cpu_time_start;
       }
       continue;
     }
 
     if (!frame.callback_pending) {
       DCHECK_GT(pending_frames.size(), 0u);
       wl_surface_set_buffer_scale(surface.get(), scale_);
+      wl_surface_damage(surface.get(), 0, 0, width_ / scale_, height_ / scale_);
       wl_surface_attach(surface.get(), pending_frames.front(), 0, 0);
       pending_frames.pop_front();
 
       frame_callback.reset(wl_surface_frame(surface.get()));
       wl_callback_add_listener(frame_callback.get(), &frame_listener, &frame);
       frame.callback_pending = true;
       wl_surface_commit(surface.get());
       wl_display_flush(display_.get());
       continue;
     }
@@ skipping 195 matching lines @@
         new std::string(command_line->GetSwitchValueASCII(switches::kUseDrm)));
   }
 
   exo::wayland::clients::MotionEvents client(
       width, height, scale, num_rects, max_frames_pending,
       command_line->HasSwitch(switches::kFullscreen),
       command_line->HasSwitch(switches::kShowFpsCounter), num_benchmark_runs,
       base::TimeDelta::FromMilliseconds(benchmark_interval_ms), use_drm.get());
   return client.Run();
 }