Apply setInterval to new surface-context pairs

BUG=83832

Review URL: http://codereview.chromium.org/6987025

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@86720 0039d316-1c4b-4281-b951-d872f2087c98

gpu/command_buffer/service/gpu_scheduler.cc

@@ -5,12 +5,14 @@
 #include "gpu/command_buffer/service/gpu_scheduler.h"
 
 #include "base/callback.h"
+#include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/debug/trace_event.h"
 #include "base/message_loop.h"
 #include "ui/gfx/gl/gl_context.h"
 #include "ui/gfx/gl/gl_bindings.h"
 #include "ui/gfx/gl/gl_surface.h"
+#include "ui/gfx/gl/gl_switches.h"
 
 using ::base::SharedMemory;
 
@@ -66,6 +68,16 @@ bool GpuScheduler::InitializeCommon(
   if (!context->MakeCurrent(surface))
     return false;
 
+#if !defined(OS_MACOSX)
+  // Set up swap interval for onscreen contexts.
+  if (!surface->IsOffscreen()) {
+    if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisableGpuVsync))
+      context->SetSwapInterval(0);
+    else
+      context->SetSwapInterval(1);
+  }
+#endif
+
   // Do not limit to a certain number of commands before scheduling another
   // update when rendering onscreen.
   if (!surface->IsOffscreen())

ui/gfx/gl/gl_context_glx.cc

@@ -119,12 +119,21 @@ void GLContextGLX::SetSwapInterval(int interval) {
     // manager. At the moment, compositing window managers don't
     // respect this setting anyway (tearing still occurs) and it
     // dramatically increases latency.
-    if (!IsCompositingWindowManagerActive(GLSurfaceGLX::GetDisplay())) {
-      glXSwapIntervalEXT(
-          GLSurfaceGLX::GetDisplay(),
-          glXGetCurrentDrawable(),
-          interval);
+    if (interval == 1 &&
+        IsCompositingWindowManagerActive(GLSurfaceGLX::GetDisplay())) {
+      LOG(INFO) <<
+          "Forcing vsync off because compositing window manager was detected.";
+      interval = 0;
     }
+    glXSwapIntervalEXT(
+        GLSurfaceGLX::GetDisplay(),
+        glXGetCurrentDrawable(),
+        interval);
+  } else {
+    if(interval == 0)
+      LOG(WARNING) <<
+          "Could not disable vsync: driver does not "
+          "support GLX_EXT_swap_control";
   }
 }