EGL contexts reference count the EGL surfaces they share....

app/gfx/gl/gl_context_egl.h

Index: app/gfx/gl/gl_context_egl.h
===================================================================
--- app/gfx/gl/gl_context_egl.h	(revision 71275)
+++ app/gfx/gl/gl_context_egl.h	(working copy)
@@ -6,8 +6,9 @@
 #define APP_GFX_GL_GL_CONTEXT_EGL_H_
 #pragma once
 
+#include "app/gfx/gl/gl_context.h"
+#include "base/ref_counted.h"
 #include "gfx/size.h"
-#include "app/gfx/gl/gl_context.h"
 
 typedef void* EGLDisplay;
 typedef void* EGLContext;
@@ -15,6 +16,20 @@
 
 namespace gfx {
 
+// Takes ownership of an EGL surface and reference counts it so it can be shared
+// by multiple EGL contexts and destroyed with the last.
+class SharedEGLSurface : public base::RefCounted<SharedEGLSurface> {
+ public:
+  explicit SharedEGLSurface(EGLSurface surface);
+  ~SharedEGLSurface();
+
+  EGLSurface egl_surface() const;
+
+ private:
+  EGLSurface surface_;
+  DISALLOW_COPY_AND_ASSIGN(SharedEGLSurface);
+};
+
 // Interface for EGL contexts. Adds an EGL specific accessor for retreiving
 // the surface.
 class BaseEGLContext : public GLContext {
@@ -27,7 +42,7 @@
   static EGLDisplay GetDisplay();
 
   // Get the associated EGL surface.
-  virtual EGLSurface GetSurface() = 0;
+  virtual SharedEGLSurface* GetSurface() = 0;
 
   // Implement GLContext.
   virtual std::string GetExtensions();
@@ -56,20 +71,21 @@
   virtual void SetSwapInterval(int interval);
 
   // Implement BaseEGLContext.
-  virtual EGLSurface GetSurface();
+  virtual SharedEGLSurface* GetSurface();
 
  private:
   void* window_;
-  EGLSurface surface_;
+  scoped_refptr<SharedEGLSurface> surface_;
   EGLContext context_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeViewEGLContext);
 };
 
 // Encapsulates an EGL OpenGL ES context intended for offscreen use. It is
-// actually associated with a native window and will render to it. The caller
-// must bind an FBO to prevent this. Not using pbuffers because ANGLE does not
-// support them.
+// actually associated with a native window or a pbuffer on supporting platforms
+// and will render to it. The caller must bind an FBO to prevent this.
+// TODO(apatrick): implement pbuffers in ANGLE and change this to
+// PbufferEGLContext and use it on all EGL platforms.
 class SecondaryEGLContext : public BaseEGLContext {
  public:
   SecondaryEGLContext();
@@ -89,12 +105,10 @@
   virtual void SetSwapInterval(int interval);
 
   // Implement BaseEGLContext.
-  virtual EGLSurface GetSurface();
+  virtual SharedEGLSurface* GetSurface();
 
  private:
-  // All offscreen
-  EGLSurface surface_;
-  bool own_surface_;
+  scoped_refptr<SharedEGLSurface> surface_;
   EGLContext context_;
 
   DISALLOW_COPY_AND_ASSIGN(SecondaryEGLContext);