aw: Do not assume functor will be called on UI thread

android_webview/browser/gl_view_renderer_manager.h

Index: android_webview/browser/gl_view_renderer_manager.h
diff --git a/android_webview/browser/gl_view_renderer_manager.h b/android_webview/browser/gl_view_renderer_manager.h
index 67595fbb4ae9461cd551bd355910cf174a63bb98..588390c8e20d5a586b9a4dbfe2804be2ff1baf4c 100644
--- a/android_webview/browser/gl_view_renderer_manager.h
+++ b/android_webview/browser/gl_view_renderer_manager.h
@@ -8,6 +8,8 @@
 #include <list>
 
 #include "base/basictypes.h"
+#include "base/synchronization/lock.h"
+#include "base/threading/platform_thread.h"
 
 namespace android_webview {
 
@@ -21,6 +23,8 @@ class GLViewRendererManager {
   GLViewRendererManager();
   ~GLViewRendererManager();
 
+  bool OnRenderThread() const;
+
   // If |key| is NullKey(), then |view| is inserted at the front and a new key
   // is returned. Otherwise |key| must point to |view| which is moved to the
   // front.
@@ -33,6 +37,10 @@ class GLViewRendererManager {
   Key NullKey();
 
  private:
+  void MarkRenderThread();
+
+  mutable base::Lock lock_;
+  base::PlatformThreadHandle render_thread_;
   ListType mru_list_;
 
   DISALLOW_COPY_AND_ASSIGN(GLViewRendererManager);