Vend common GL context

ui/gfx/compositor/compositor.h

Index: ui/gfx/compositor/compositor.h
diff --git a/ui/gfx/compositor/compositor.h b/ui/gfx/compositor/compositor.h
index df575ddad11972f4fe6a7c6b4d8e3c8811c48404..42bb770cd756f0958b3a5db73b2f4e88310a5026 100644
--- a/ui/gfx/compositor/compositor.h
+++ b/ui/gfx/compositor/compositor.h
@@ -10,18 +10,18 @@
 #include "ui/gfx/compositor/compositor_export.h"
 #include "ui/gfx/transform.h"
 #include "ui/gfx/native_widget_types.h"
+#include "ui/gfx/size.h"
 
 class SkCanvas;
 namespace gfx {
 class Point;
 class Rect;
-class Size;
 }
 
 namespace ui {
 
 struct TextureDrawParams {
-  TextureDrawParams() : transform(), blend(false) {}
+  TextureDrawParams() : transform(), blend(false), compositor_size() {}
 
   // The transform to be applied to the texture.
   ui::Transform transform;
@@ -30,6 +30,9 @@ struct TextureDrawParams {
   // Otherwise, the drawn pixels clobber the old pixels.
   bool blend;
 
+  // The size of the surface that the texture is drawn to.
+  gfx::Size compositor_size;
+
   // Copy and assignment are allowed.
 };
 
@@ -91,12 +94,23 @@ class COMPOSITOR_EXPORT Compositor : public base::RefCounted<Compositor> {
 
   // Notifies the compositor that the size of the widget that it is
   // drawing to has changed.
-  virtual void OnWidgetSizeChanged(const gfx::Size& size) = 0;
+  void WidgetSizeChanged(const gfx::Size& size) {
+    size_ = size;
+    OnWidgetSizeChanged();
+  }
+
+  // Returns the size of the widget that is being drawn to.
+  const gfx::Size& size() { return size_; }
 
  protected:
+  explicit Compositor(const gfx::Size& size) : size_(size) {}
   virtual ~Compositor() {}
 
+  virtual void OnWidgetSizeChanged() = 0;
+
  private:
+  gfx::Size size_;
+
   friend class base::RefCounted<Compositor>;
 };