[Metrics] Move CachingPermutedEntropyProvider into the variations component.

chrome/common/pref_names.h

 // Copyright (c) 2012 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.
 
 // Constants for the names of various preferences, for easier changing.
 
 #ifndef CHROME_COMMON_PREF_NAMES_H_
 #define CHROME_COMMON_PREF_NAMES_H_
 
 #include <stddef.h>
@@ skipping 410 matching lines @@
 
 extern const char kGLVendorString[];
 extern const char kGLRendererString[];
 extern const char kGLVersionString[];
 
 extern const char kEulaAccepted[];
 
 extern const char kMetricsClientID[];
 extern const char kMetricsSessionID[];
 extern const char kMetricsLowEntropySource[];
-extern const char kMetricsPermutedEntropyCache[];
 extern const char kMetricsOldClientID[];
 extern const char kMetricsOldLowEntropySource[];
 extern const char kMetricsReportingEnabled[];
 extern const char kMetricsReportingEnabledTimestamp[];
 extern const char kMetricsMachineId[];
 extern const char kMetricsResetIds[];
 // Android has it's own metric / crash reporting implemented in Android
 // Java code so kMetricsReportingEnabled doesn't make sense. We use this
 // to inform crashes_ui that we have enabled crash reporting.
 #if defined(OS_ANDROID)
@@ skipping 436 matching lines @@
 
 #if defined(OS_ANDROID)
 extern const char kPartnerBookmarkMappings[];
 #endif
 
 extern const char kQuickCheckEnabled[];
 
 }  // namespace prefs
 
 #endif  // CHROME_COMMON_PREF_NAMES_H_