Add an IPC method for Blink to call RapporService::RecordSample()

chrome/renderer/chrome_content_renderer_client.h

Index: chrome/renderer/chrome_content_renderer_client.h
diff --git a/chrome/renderer/chrome_content_renderer_client.h b/chrome/renderer/chrome_content_renderer_client.h
index 3647004cbff826e932347170cf8565d74fc6c711..81b462999826f8e4b0adbb8e339d55d33247f8aa 100644
--- a/chrome/renderer/chrome_content_renderer_client.h
+++ b/chrome/renderer/chrome_content_renderer_client.h
@@ -174,6 +174,9 @@ class ChromeContentRendererClient : public content::ContentRendererClient {
 
   static bool WasWebRequestUsedBySomeExtensions();
 
+  void RecordRappor(
+    const std::string& metric, const std::string& sample) override;

[jam, 2015/04/02 16:24:14]

nit: this should match the order of the interface, and also there shouldn't be
these blank lines. so moved this up to 

[kojii, 2015/04/03 06:50:53]

Done -- to be precise, methods above are not in the order of interface, so I put
as the last one to override. Hope this is ok?

+
  private:
   FRIEND_TEST_ALL_PREFIXES(ChromeContentRendererClientTest, NaClRestriction);
   FRIEND_TEST_ALL_PREFIXES(ChromeContentRendererClientTest,