Add build and patch to Chrome-Proxy header

chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.h

Index: chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.h
diff --git a/chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.h b/chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.h
index 72f502680d8ed233185194e99def581fad7c3de3..17af6cf2275be805753c00e0a1fd8c9011df0d3d 100644
--- a/chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.h
+++ b/chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.h
@@ -55,10 +55,18 @@ class DataReductionProxyChromeSettings
   static std::string GetClient();
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(DataReductionProxyChromeSettingsTest,
+                           TestGetBuildAndPatchNumber);
+
   // Registers the DataReductionProxyEnabled synthetic field trial with
   // the group |data_reduction_proxy_enabled|.
   void RegisterSyntheticFieldTrial(bool data_reduction_proxy_enabled);
 
+  // Using |version|, returns the build and patch portion of the string
+  // delimited by a period. If |version| isn't of the form xx.xx.xx.xx returns
+  // an empty string.
+  static std::string GetBuildAndPatchNumberFromString(std::string version);
+
   DISALLOW_COPY_AND_ASSIGN(DataReductionProxyChromeSettings);
 };