Route D3D VSync signal to Compositor

ui/gl/gl_switches.cc

Index: ui/gl/gl_switches.cc
diff --git a/ui/gl/gl_switches.cc b/ui/gl/gl_switches.cc
index dbf0e6e153ee2a27426214deb21332ea82e20719..cb4995fb298c10bb7b6bcd464641deb2df19a2bd 100644
--- a/ui/gl/gl_switches.cc
+++ b/ui/gl/gl_switches.cc
@@ -112,6 +112,10 @@ const char kDisableGLExtensions[] = "disable-gl-extensions";
 // Use EGL_KHR_swap_buffers_with_damage to implement PostSubBuffers
 const char kEnableSwapBuffersWithDamage[] = "enable-swap-buffers-with-damage";
 
+// Wait for D3D VSync signals in GPU process (as opposed to delay based VSync
+// generated in Browser process based on VSync parameters).
+const char kUseD3DVSync[] = "use-d3d-vsync";
+
 // This is the list of switches passed from this file that are passed from the
 // GpuProcessHost to the GPU Process. Add your switch to this list if you need
 // to read it in the GPU process, else don't add it.
@@ -127,6 +131,7 @@ const char* kGLSwitchesCopiedFromGpuProcessHost[] = {
     kUseANGLE,
     kDisableDirectComposition,
     kEnableSwapBuffersWithDamage,
+    kUseD3DVSync
 };
 const int kGLSwitchesCopiedFromGpuProcessHostNumSwitches =
     arraysize(kGLSwitchesCopiedFromGpuProcessHost);