webkit: expose webkit branch and revision number in about pages

webkit/glue/user_agent.h

Index: webkit/glue/user_agent.h
diff --git a/webkit/glue/user_agent.h b/webkit/glue/user_agent.h
index 3d1f7880d57775320c8c380b935c076e4c2e8348..d63f758bd50d93f6fd4dbf8ed12123951847daea 100644
--- a/webkit/glue/user_agent.h
+++ b/webkit/glue/user_agent.h
@@ -22,6 +22,12 @@ std::string BuildOSCpuInfo();
 // Returns the WebKit version (major.minor).
 std::string GetWebKitVersion();
 
+// Get the WebKit revision (e.g. http://path/to/branch@revision).
+// (We don't expose this in the user-agent string, but this file is a
+// natural location for this functionality).
+std::string GetWebKitRevision();
+
+
 }  // namespace webkit_glue
 
 #endif  // WEBKIT_GLUE_USER_AGENT_H_