Implement kCurrentThemeID so we can know what the last theme to be installed ...

chrome/test/testing_profile.h

Index: chrome/test/testing_profile.h
===================================================================
--- chrome/test/testing_profile.h	(revision 22263)
+++ chrome/test/testing_profile.h	(working copy)
@@ -138,6 +138,9 @@
   virtual void SetTheme(Extension* extension) { }
   virtual void SetNativeTheme() { }
   virtual void ClearTheme() { }
+  virtual Extension* GetTheme() {
+    return NULL;
+  }
   virtual ThemeProvider* GetThemeProvider() {
     return theme_provider_.get();
   }