Refactor SetOmahaExperimentLabel out of gcpai and into install_util.

chrome/installer/util/install_util.h

Index: chrome/installer/util/install_util.h
diff --git a/chrome/installer/util/install_util.h b/chrome/installer/util/install_util.h
index a2588159010400065c10f8ce329e95a6f82b5c08..e737016eb42e079af526c89ce8e55129424e147b 100644
--- a/chrome/installer/util/install_util.h
+++ b/chrome/installer/util/install_util.h
@@ -175,6 +175,11 @@ class InstallUtil {
   // Returns a string in the form YYYYMMDD of the current date.
   static string16 GetCurrentDate();
 
+  // Sets |experiment_label| as the Omaha experiment label for the Chrome
+  // product registry entries for a given |registry_hive|.
+  static bool SetOmahaExperimentLabel(const string16& experiment_label,
+                                      HKEY registry_hive);
+
   // A predicate that compares the program portion of a command line with a
   // given file path.  First, the file paths are compared directly.  If they do
   // not match, the filesystem is consulted to determine if the paths reference