Clean up UMA 3g experiment and unify metrics enabled pref for Android

chrome/browser/metrics/chrome_metrics_service_accessor_unittest.cc

 // 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.
 
 #include "chrome/browser/metrics/chrome_metrics_service_accessor.h"
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/macros.h"
 #include "build/build_config.h"
@@ skipping 16 matching lines @@
 
  private:
   content::TestBrowserThreadBundle thread_bundle_;
   ScopedTestingLocalState testing_local_state_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeMetricsServiceAccessorTest);
 };
 
 TEST_F(ChromeMetricsServiceAccessorTest, MetricsReportingEnabled) {
 #if defined(GOOGLE_CHROME_BUILD)
-#if !defined(OS_CHROMEOS)
-#if defined(OS_ANDROID)
-  const char* pref = prefs::kCrashReportingEnabled;
-#else
   const char* pref = metrics::prefs::kMetricsReportingEnabled;
-#endif  // defined(OS_ANDROID)
   GetLocalState()->SetDefaultPrefValue(pref, new base::FundamentalValue(false));
 
   GetLocalState()->SetBoolean(pref, false);
   EXPECT_FALSE(
       ChromeMetricsServiceAccessor::IsMetricsAndCrashReportingEnabled());
   GetLocalState()->SetBoolean(pref, true);
   EXPECT_TRUE(
       ChromeMetricsServiceAccessor::IsMetricsAndCrashReportingEnabled());
   GetLocalState()->ClearPref(pref);
   EXPECT_FALSE(
       ChromeMetricsServiceAccessor::IsMetricsAndCrashReportingEnabled());
 
   // If field trials are forced, metrics should always be disabled, regardless
   // of the value of the pref.
   base::CommandLine::ForCurrentProcess()->AppendSwitch(
       switches::kForceFieldTrials);
   EXPECT_FALSE(
       ChromeMetricsServiceAccessor::IsMetricsAndCrashReportingEnabled());
   GetLocalState()->SetBoolean(pref, true);
   EXPECT_FALSE(
       ChromeMetricsServiceAccessor::IsMetricsAndCrashReportingEnabled());
-#endif  // !defined(OS_CHROMEOS)
 #else
   // Metrics Reporting is never enabled when GOOGLE_CHROME_BUILD is undefined.
   EXPECT_FALSE(
       ChromeMetricsServiceAccessor::IsMetricsAndCrashReportingEnabled());
 #endif
 }