Cleanup: Remove unneeded includes of notification_service.h in other headers....

chrome/browser/extensions/extension_metrics_apitest.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <map>
 
 #include "base/metrics/histogram.h"
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/notification_registrar.h"
+#include "chrome/common/notification_service.h"
 
 namespace {
 
 // The tests that are run by this extension are expected to record the following
 // user actions, with the specified counts.  If the tests in test.js are
 // modified, this array may need to be updated.
 struct RecordedUserAction {
   const char* name;  // base name of metric without extension id.
   int count;  // number of times the metric was recorded.
 } g_user_actions[] = {
@@ skipping 124 matching lines @@
 
   ASSERT_TRUE(RunExtensionTest("metrics")) << message_;
   const Extension* extension = GetSingleLoadedExtension();
   ASSERT_TRUE(extension);
 
   observer.ValidateUserActions(extension,
                                g_user_actions,
                                arraysize(g_user_actions));
   ValidateHistograms(extension, g_histograms, arraysize(g_histograms));
 }