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

chrome/browser/metrics/extensions_metrics_provider_unittest.cc

Index: chrome/browser/metrics/extensions_metrics_provider_unittest.cc
diff --git a/chrome/browser/metrics/extensions_metrics_provider_unittest.cc b/chrome/browser/metrics/extensions_metrics_provider_unittest.cc
index bd6b4472d18b0318b8cf0c76043b9977dc00e544..934e2bffc2a04a10d1ed29744b33b0e46ebf021a 100644
--- a/chrome/browser/metrics/extensions_metrics_provider_unittest.cc
+++ b/chrome/browser/metrics/extensions_metrics_provider_unittest.cc
@@ -6,9 +6,9 @@
 
 #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"
@@ -28,8 +28,8 @@ bool IsMetricsReportingEnabled() {
 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 {
@@ -44,9 +44,9 @@ class TestExtensionsMetricsProvider : public ExtensionsMetricsProvider {
  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()
@@ -109,12 +109,10 @@ 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());