[Extensions] Improve app custom bindings

chrome/renderer/extensions/app_bindings.h

Index: chrome/renderer/extensions/app_bindings.h
diff --git a/chrome/renderer/extensions/app_bindings.h b/chrome/renderer/extensions/app_bindings.h
index 63b59966ff1d34b338a6f15749f53bb6bf9234ab..9f1feadc54dd233801dfe8a854aab5e124e9e3f3 100644
--- a/chrome/renderer/extensions/app_bindings.h
+++ b/chrome/renderer/extensions/app_bindings.h
@@ -11,11 +11,13 @@
 #ifndef CHROME_RENDERER_EXTENSIONS_APP_BINDINGS_H_
 #define CHROME_RENDERER_EXTENSIONS_APP_BINDINGS_H_
 
-#include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "chrome/renderer/extensions/chrome_v8_extension_handler.h"
 #include "extensions/renderer/object_backed_native_handler.h"
-#include "third_party/WebKit/public/web/WebFrame.h"
+
+namespace blink {
+class WebLocalFrame;
+}
 
 namespace extensions {
 class Dispatcher;