Ozone: Avoid blocking in Swapbuffer Call.

ui/gl/gl_surface_ozone.cc

Index: ui/gl/gl_surface_ozone.cc
diff --git a/ui/gl/gl_surface_ozone.cc b/ui/gl/gl_surface_ozone.cc
index 67ab131b7a8c261905ca7fe5bc0a5aef855e2adb..374c71cff141d207d091070e6a7917fdf6ebaa57 100644
--- a/ui/gl/gl_surface_ozone.cc
+++ b/ui/gl/gl_surface_ozone.cc
@@ -4,8 +4,10 @@
 
 #include "ui/gl/gl_surface.h"
 
+#include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_image.h"
@@ -99,13 +101,18 @@ class GL_EXPORT GLSurfaceOzoneEGL : public NativeViewGLSurfaceEGL {
   DISALLOW_COPY_AND_ASSIGN(GLSurfaceOzoneEGL);
 };
 
-class GL_EXPORT GLSurfaceOzoneSurfaceless : public SurfacelessEGL {
+class GL_EXPORT GLSurfaceOzoneSurfaceless : public SurfacelessEGL,
+                    public base::SupportsWeakPtr<GLSurfaceOzoneSurfaceless> {
  public:
   GLSurfaceOzoneSurfaceless(scoped_ptr<ui::SurfaceOzoneEGL> ozone_surface,
                             AcceleratedWidget widget)
       : SurfacelessEGL(gfx::Size()),
         ozone_surface_(ozone_surface.Pass()),
-        widget_(widget) {}
+        widget_(widget) {
+    ozone_surface_->SetPageFlipCompletionCallback(
+        base::Bind(&GLSurfaceOzoneSurfaceless::PageFlipCompleted,
+            this->AsWeakPtr()));
+  }
 
   virtual bool Initialize() override {
     if (!SurfacelessEGL::Initialize())
@@ -145,6 +152,16 @@ class GL_EXPORT GLSurfaceOzoneSurfaceless : public SurfacelessEGL {
     return true;
   }
 
+  void SetPageFlipCompletionCallback(
+      const PageFlipCompletionCallback& callback) override {
+    page_flip_completion_callback_ = callback;
+  }
+
+  void PageFlipCompleted() {
+    DCHECK(!page_flip_completion_callback_.is_null());
+    page_flip_completion_callback_.Run();
+  }
+
  private:
   virtual ~GLSurfaceOzoneSurfaceless() {
     Destroy();  // EGL surface must be destroyed before SurfaceOzone
@@ -154,6 +171,7 @@ class GL_EXPORT GLSurfaceOzoneSurfaceless : public SurfacelessEGL {
   scoped_ptr<ui::SurfaceOzoneEGL> ozone_surface_;
   AcceleratedWidget widget_;
   scoped_ptr<VSyncProvider> vsync_provider_;
+  PageFlipCompletionCallback page_flip_completion_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(GLSurfaceOzoneSurfaceless);
 };