glx: forward Expose event from child window to parent

ui/gl/gl_surface_glx.h

Index: ui/gl/gl_surface_glx.h
diff --git a/ui/gl/gl_surface_glx.h b/ui/gl/gl_surface_glx.h
index 58088a75c130759c55c555237aba425d5373470e..37c835c7e167223d011fc203f6ad7681169cd946 100644
--- a/ui/gl/gl_surface_glx.h
+++ b/ui/gl/gl_surface_glx.h
@@ -8,6 +8,7 @@
 #include <string>
 
 #include "base/compiler_specific.h"
+#include "ui/events/platform/platform_event_dispatcher.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/size.h"
 #include "ui/gfx/vsync_provider.h"
@@ -48,7 +49,8 @@ class GL_EXPORT GLSurfaceGLX : public GLSurface {
 };
 
 // A surface used to render to a view.
-class GL_EXPORT NativeViewGLSurfaceGLX : public GLSurfaceGLX {
+class GL_EXPORT NativeViewGLSurfaceGLX : public GLSurfaceGLX,
+                                         public ui::PlatformEventDispatcher {
  public:
   explicit NativeViewGLSurfaceGLX(gfx::AcceleratedWidget window);
 
@@ -66,13 +68,16 @@ class GL_EXPORT NativeViewGLSurfaceGLX : public GLSurfaceGLX {
   virtual VSyncProvider* GetVSyncProvider() OVERRIDE;
 
  protected:
-  NativeViewGLSurfaceGLX();
   virtual ~NativeViewGLSurfaceGLX();
 
  private:
   // The handle for the drawable to make current or swap.
   gfx::AcceleratedWidget GetDrawableHandle() const;
 
+  // PlatformEventDispatcher implementation
+  virtual bool CanDispatchEvent(const ui::PlatformEvent& event) OVERRIDE;
+  virtual uint32_t DispatchEvent(const ui::PlatformEvent& event) OVERRIDE;
+
   // Window passed in at creation. Always valid.
   gfx::AcceleratedWidget parent_window_;