[Metrics] Move CachingPermutedEntropyProvider into the variations component.

components/variations/caching_permuted_entropy_provider.h

 // Copyright 2013 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_COMMON_METRICS_CACHING_PERMUTED_ENTROPY_PROVIDER_H_
-#define CHROME_COMMON_METRICS_CACHING_PERMUTED_ENTROPY_PROVIDER_H_
+#ifndef COMPONENTS_VARIATIONS_CACHING_PERMUTED_ENTROPY_PROVIDER_H_
+#define COMPONENTS_VARIATIONS_CACHING_PERMUTED_ENTROPY_PROVIDER_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/threading/thread_checker.h"
-#include "chrome/common/metrics/proto/permuted_entropy_cache.pb.h"
 #include "components/variations/entropy_provider.h"
+#include "components/variations/proto/permuted_entropy_cache.pb.h"

[blundell, 2014/05/19 11:04:32]

I believe that the target generating the headers from the protos needs to be
distinct from the target in which this file is built so that the target in which
this file is built can depend on it and thus ensure that the headers are present
at build time.

[Ilya Sherman, 2014/05/19 11:16:27]

Done.

 
 class PrefService;
 class PrefRegistrySimple;
 
 namespace metrics {

[blundell, 2014/05/19 11:04:32]

namespace variations? (in all the moved files)

[Ilya Sherman, 2014/05/19 11:16:27]

Ack.  (See my reply on the other file.)

 
 // CachingPermutedEntropyProvider is an entropy provider that uses the same
 // algorithm as the PermutedEntropyProvider, but caches the results in Local
 // State between runs.
 class CachingPermutedEntropyProvider : public PermutedEntropyProvider {
  public:
   // Creates a CachingPermutedEntropyProvider using the given |local_state|
   // prefs service with the specified |low_entropy_source|, which should have a
   // value in the range of [0, low_entropy_source_max).
   CachingPermutedEntropyProvider(PrefService* local_state,
@@ skipping 27 matching lines @@
 
   base::ThreadChecker thread_checker_;
   PrefService* local_state_;
   mutable PermutedEntropyCache cache_;
 
   DISALLOW_COPY_AND_ASSIGN(CachingPermutedEntropyProvider);
 };
 
 }  // namespace metrics
 
-#endif  // CHROME_COMMON_METRICS_CACHING_PERMUTED_ENTROPY_PROVIDER_H_
+#endif  // COMPONENTS_VARIATIONS_CACHING_PERMUTED_ENTROPY_PROVIDER_H_