Allow textures to be moved from one GL context group to another.

gpu/command_buffer/service/context_group.h

Index: gpu/command_buffer/service/context_group.h
===================================================================
--- gpu/command_buffer/service/context_group.h	(revision 132415)
+++ gpu/command_buffer/service/context_group.h	(working copy)
@@ -22,6 +22,7 @@
 
 namespace gles2 {
 
+class Display;
 class GLES2Decoder;
 class BufferManager;
 class FramebufferManager;
@@ -37,7 +38,7 @@
  public:
   typedef scoped_refptr<ContextGroup> Ref;
 
-  explicit ContextGroup(bool bind_generates_resource);
+  explicit ContextGroup(Display* display, bool bind_generates_resource);
   ~ContextGroup();
 
   // This should only be called by GLES2Decoder. This must be paired with a
@@ -49,6 +50,10 @@
   // It should only be called by GLES2Decoder.
   void Destroy(bool have_context);
 
+  Display* display() const {
+    return display_.get();
+  }
+
   bool bind_generates_resource() {
     return bind_generates_resource_;
   }
@@ -112,6 +117,8 @@
   IdAllocatorInterface* GetIdAllocator(unsigned namespace_id);
 
  private:
+  scoped_refptr<Display> display_;
+
   // Whether or not this context is initialized.
   int num_contexts_;
   bool bind_generates_resource_;