Convert //chrome/browser/metrics from scoped_ptr to std::unique_ptr

chrome/browser/metrics/extensions_metrics_provider_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/extensions_metrics_provider.h"
 
 #include <stdint.h>
 
+#include <memory>
 #include <string>
 
-#include "base/memory/scoped_ptr.h"
 #include "components/metrics/client_info.h"
 #include "components/metrics/metrics_service.h"
 #include "components/metrics/metrics_state_manager.h"
 #include "components/metrics/proto/system_profile.pb.h"
 #include "components/prefs/testing_pref_service.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/extension_builder.h"
 #include "extensions/common/extension_set.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 
 bool IsMetricsReportingEnabled() {
   return true;
 }
 
 void StoreNoClientInfoBackup(const metrics::ClientInfo& /* client_info */) {
 }
 
-scoped_ptr<metrics::ClientInfo> ReturnNoBackup() {
-  return scoped_ptr<metrics::ClientInfo>();
+std::unique_ptr<metrics::ClientInfo> ReturnNoBackup() {
+  return std::unique_ptr<metrics::ClientInfo>();

[Ilya Sherman, 2016/04/14 00:59:53]

nit: Is "return nullptr;" equivalent here?

[dcheng, 2016/04/14 01:05:24]

Yes. But largely out of scope unless someone strongly insists. We have a lot of
code that does this currently, so fixing just the ones people comment on is a
drop in the ocean.

I'm hoping that clang-tidy integration will help us find these and clean them up
on a systemic basis.

 }
 
 class TestExtensionsMetricsProvider : public ExtensionsMetricsProvider {
  public:
   explicit TestExtensionsMetricsProvider(
       metrics::MetricsStateManager* metrics_state_manager)
       : ExtensionsMetricsProvider(metrics_state_manager) {}
 
   // Makes the protected HashExtension method available to testing code.
   using ExtensionsMetricsProvider::HashExtension;
 
  protected:
   // Override the GetInstalledExtensions method to return a set of extensions
   // for tests.
-  scoped_ptr<extensions::ExtensionSet> GetInstalledExtensions(
+  std::unique_ptr<extensions::ExtensionSet> GetInstalledExtensions(
       Profile* profile) override {
-    scoped_ptr<extensions::ExtensionSet> extensions(
+    std::unique_ptr<extensions::ExtensionSet> extensions(

[Ilya Sherman, 2016/04/14 00:59:53]

nit: It looks like this code be base::WrapUnique, as could many of the other
call sites.  Is converting over out of scope for this CL?

[dcheng, 2016/04/14 01:05:24]

Sometimes: this particular instance is probably better to write the way it's
already written. A potential improvement in the future:

auto extensions = base::MakeUnique<ExtensionSet>();

But that's still in debate, as is allowing the use of auto to elide a smart
pointer type.

         new extensions::ExtensionSet());
     scoped_refptr<const extensions::Extension> extension;
     extension = extensions::ExtensionBuilder()
                     .SetManifest(extensions::DictionaryBuilder()
                                      .Set("name", "Test extension")
                                      .Set("version", "1.0.0")
                                      .Set("manifest_version", 2)
                                      .Build())
                     .SetID("ahfgeienlihckogmohjhadlkjgocpleb")
                     .Build();
@@ skipping 42 matching lines @@
             TestExtensionsMetricsProvider::HashExtension(
                 "mdhofdjgenpkhlmddfaegdjddcecipmo", 3817));
 }
 
 // Checks that the fake set of extensions provided by
 // TestExtensionsMetricsProvider is encoded properly.
 TEST(ExtensionsMetricsProvider, SystemProtoEncoding) {
   metrics::SystemProfileProto system_profile;
   TestingPrefServiceSimple local_state;
   metrics::MetricsService::RegisterPrefs(local_state.registry());
-  scoped_ptr<metrics::MetricsStateManager> metrics_state_manager(
+  std::unique_ptr<metrics::MetricsStateManager> metrics_state_manager(
       metrics::MetricsStateManager::Create(
-          &local_state,
-          base::Bind(&IsMetricsReportingEnabled),
-          base::Bind(&StoreNoClientInfoBackup),
-          base::Bind(&ReturnNoBackup)));
+          &local_state, base::Bind(&IsMetricsReportingEnabled),
+          base::Bind(&StoreNoClientInfoBackup), base::Bind(&ReturnNoBackup)));
   TestExtensionsMetricsProvider extension_metrics(metrics_state_manager.get());
   extension_metrics.ProvideSystemProfileMetrics(&system_profile);
   ASSERT_EQ(2, system_profile.occupied_extension_bucket_size());
   EXPECT_EQ(10, system_profile.occupied_extension_bucket(0));
   EXPECT_EQ(1007, system_profile.occupied_extension_bucket(1));
 }