Apply setInterval to new surface-context pairs

ui/gfx/gl/gl_context_glx.cc

 // Copyright (c) 2011 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.
 
 extern "C" {
 #include <X11/Xlib.h>
 }
 
 #include "ui/gfx/gl/gl_context_glx.h"
 
@@ skipping 101 matching lines @@
   return context_;
 }
 
 void GLContextGLX::SetSwapInterval(int interval) {
   DCHECK(IsCurrent(NULL));
   if (HasExtension("GLX_EXT_swap_control") && glXSwapIntervalEXT) {
     // Only enable vsync if we aren't using a compositing window
     // 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";
   }
 }
 
 std::string GLContextGLX::GetExtensions() {
   DCHECK(IsCurrent(NULL));
   const char* extensions = glXQueryExtensionsString(
       GLSurfaceGLX::GetDisplay(),
       0);
   if (extensions) {
     return GLContext::GetExtensions() + " " + extensions;
   }
 
   return GLContext::GetExtensions();
 }
 
 }  // namespace gfx