Support presentation callback for GLSurfaceOSMesaX11

Bug: 776877
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: Ia388f02926202777ac9c7461715947ed97e2082b
Reviewed-on: https://chromium-review.googlesource.com/1011675Reviewed-by: Antoine Labour <piman@chromium.org>
Commit-Queue: Peng Huang <penghuang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551090}

ui/gl/gl_surface_osmesa_x11.cc

@@ -159,8 +159,6 @@ gfx::SwapResult GLSurfaceOSMesaX11::PostSubBuffer(
     int width,
     int height,
     const PresentationCallback& callback) {
-  // TODO(penghuang): Provide useful presentation feedback.
-  // https://crbug.com/776877
   gfx::Size size = GetSize();
 
   // Move (0,0) from lower-left to upper-left
@@ -182,9 +180,20 @@ gfx::SwapResult GLSurfaceOSMesaX11::PostSubBuffer(
   XCopyArea(xdisplay_, pixmap_, window_, window_graphics_context_, x, y, width,
             height, x, y);
 
+  constexpr int64_t kRefreshIntervalInMicroseconds =
+      base::Time::kMicrosecondsPerSecond / 60;
+  callback.Run(gfx::PresentationFeedback(
+      base::TimeTicks::Now(),
+      base::TimeDelta::FromMicroseconds(kRefreshIntervalInMicroseconds),
+      0 /* flags */));
+
   return gfx::SwapResult::SWAP_ACK;
 }
 
+bool GLSurfaceOSMesaX11::SupportsPresentationCallback() {
+  return true;
+}
+
 GLSurfaceOSMesaX11::~GLSurfaceOSMesaX11() {
   Destroy();
 }

ui/gl/gl_surface_osmesa_x11.h

@@ -37,6 +37,7 @@ class GL_EXPORT GLSurfaceOSMesaX11 : public GLSurfaceOSMesa {
                                 int width,
                                 int height,
                                 const PresentationCallback& callback) override;
+  bool SupportsPresentationCallback() override;
 
  protected:
   ~GLSurfaceOSMesaX11() override;