Collect separate V8 histograms for Top10 non-Google sites

content/renderer/render_thread_impl.h

Index: content/renderer/render_thread_impl.h
diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index 2dcd6a5b5f4ba5f34dd43cb8cb6edf5cc7d6bceb..236da9f6a3509cfc8455ec7d44e482436474f8fe 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h
@@ -382,8 +382,16 @@ class CONTENT_EXPORT RenderThreadImpl
     std::string ConvertToCustomHistogramName(const char* histogram_name) const;
 
    private:
+    FRIEND_TEST_ALL_PREFIXES(RenderThreadImplUnittest,
+                             IdentifyAlexaTop10NonGoogleSite);
     friend class RenderThreadImplUnittest;
 
+    // Converts a host name to a suffix for histograms
+    std::string HostToCustomHistogramSuffix(const std::string& host);
+
+    // Helper function to identify a certain set of top pages
+    bool IsAlexaTop10NonGoogleSite(const std::string& host);
+
     // Used for updating the information on which is the common host which all
     // RenderView's share (if any). If there is no common host, this function is
     // called with an empty string.