Add feature use counting for window.external.AddSearchProvider (Blink side).

third_party/WebKit/public/web/WebFrame.h

Index: third_party/WebKit/public/web/WebFrame.h
diff --git a/third_party/WebKit/public/web/WebFrame.h b/third_party/WebKit/public/web/WebFrame.h
index ee3a1b42d12eff522d8215da2f6f4b6c8d6d71c3..0f4077dd0e8facc89d07f6411ebbedfa33f6338a 100644
--- a/third_party/WebKit/public/web/WebFrame.h
+++ b/third_party/WebKit/public/web/WebFrame.h
@@ -118,6 +118,11 @@ public:
         TextGranularityLast = WordGranularity,
     };
 
+    enum Feature {
+        ExternalAddSearchProvider = 0,
+        ExternalIsSearchProviderInstalled,
+    };
+
     // Returns the number of live WebFrame objects, used for leak checking.
     BLINK_EXPORT static int instanceCount();
 
@@ -696,6 +701,8 @@ public:
 #endif
 #endif
 
+    virtual void countFeatureUse(Feature) = 0;
+
 protected:
     explicit WebFrame(WebTreeScopeType);
     virtual ~WebFrame();