First cut at custom user style sheets.

chrome/test/testing_profile.h

Index: chrome/test/testing_profile.h
diff --git a/chrome/test/testing_profile.h b/chrome/test/testing_profile.h
index 31711fe8a96ac81c7c4514a8125d14663ec87e55..214d70af72d24a0db2471621d4ffdec692f1fc7c 100644
--- a/chrome/test/testing_profile.h
+++ b/chrome/test/testing_profile.h
@@ -184,6 +184,7 @@ class TestingProfile : public Profile {
 
   virtual net::SSLConfigService* GetSSLConfigService() { return NULL; }
   virtual Blacklist* GetPrivacyBlacklist() { return NULL; }
+  virtual UserStyleSheetWatcher* GetUserStyleSheetWatcher() { return NULL; }
   virtual HostContentSettingsMap* GetHostContentSettingsMap() {
     if (!host_content_settings_map_.get())
       host_content_settings_map_ = new HostContentSettingsMap(this);