Remove ClonedInstallDetector/MachineIdProvider //content dependencies

chrome/browser/metrics/cloned_install_detector.h

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_METRICS_CLONED_INSTALL_DETECTOR_H_
 #define CHROME_BROWSER_METRICS_CLONED_INSTALL_DETECTOR_H_
 
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 
 class PrefRegistrySimple;
 class PrefService;
 
+namespace base {
+class SingleThreadTaskRunner;
+}
+
 namespace metrics {
 
 class MachineIdProvider;
 
 // A class for detecting if an install is cloned. It does this by detecting
 // when the hardware running Chrome changes.
 class ClonedInstallDetector {
  public:
   explicit ClonedInstallDetector(MachineIdProvider* raw_id_provider);
   virtual ~ClonedInstallDetector();
 
-  // Posts a task to generate a machine ID and store it to a local state pref.
-  // If the newly generated ID is different than the previously stored one, then
-  // the install is considered cloned. The ID is a 24-bit value based off of
-  // machine characteristics. This value should never be sent over the network.
+  // Posts a task to |task_runner| to generate a machine ID and store it to a
+  // local state pref. If the newly generated ID is different than the
+  // previously stored one, then the install is considered cloned. The ID is a
+  // 24-bit value based off of machine characteristics. This value should never
+  // be sent over the network.
   // TODO(jwd): Implement change detection.
-  void CheckForClonedInstall(PrefService* local_state);
+  void CheckForClonedInstall(
+      PrefService* local_state,
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
 
   static void RegisterPrefs(PrefRegistrySimple* registry);
 
  private:
   FRIEND_TEST_ALL_PREFIXES(ClonedInstallDetectorTest, SaveId);
   FRIEND_TEST_ALL_PREFIXES(ClonedInstallDetectorTest, DetectClone);
 
   // Converts raw_id into a 24-bit hash and stores the hash in |local_state|.
   // |raw_id| is not a const ref because it's passed from a cross-thread post
   // task.
   void SaveMachineId(PrefService* local_state, std::string raw_id);
 
   scoped_refptr<MachineIdProvider> raw_id_provider_;
   base::WeakPtrFactory<ClonedInstallDetector> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ClonedInstallDetector);
 };
 
 }  // namespace metrics
 
 #endif  // CHROME_BROWSER_METRICS_CLONED_INSTALL_DETECTOR_H_