metrics: Replace 'OVERRIDE' with 'override' and fix linter

Replace OVERRIDE macro with native C++ 'override' keyword.
Also fixed the style issue of using both 'override' and 'virtual'
on member function overrides. Only one is required and cpplint
complains if both are specified now.

And since gobi-chromo-plugin is the only project that uses
libmetrics and is not C++11 yet, enabled C++11 features
in its makefile to allow for the 'override' keywords to
compile in the included metrics/metrics_library.h header.

BUG=None
TEST=USE="cellular buffet" ./build_packages

Change-Id: I28dace6dc4bcb07386632eaed890ce41564e8144
Reviewed-on: https://chromium-review.googlesource.com/212494
Reviewed-by: Ben Chan <benchan@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
Tested-by: Alex Vakulenko <avakulenko@chromium.org>

metrics/metrics_library.h

@@ -34,7 +34,7 @@ class MetricsLibrary : public MetricsLibraryInterface {
   virtual ~MetricsLibrary();
 
   // Initializes the library.
-  virtual void Init() OVERRIDE;
+  void Init() override;
 
   // Returns whether or not the machine is running in guest mode.
   bool IsGuestMode();
@@ -76,15 +76,13 @@ class MetricsLibrary : public MetricsLibraryInterface {
   // histogram is proportional to the number of buckets. Therefore, it
   // is strongly recommended to keep this number low (e.g., 50 is
   // normal, while 100 is high).
-  virtual bool SendEnumToUMA(const std::string& name,
-                             int sample,
-                             int max) OVERRIDE;
+  bool SendEnumToUMA(const std::string& name, int sample, int max) override;
 
   // Sends sparse histogram sample to Chrome for transport to UMA.  Returns
   // true on success.
   //
   // |sample| is the 32-bit integer value to be recorded.
-  virtual bool SendSparseToUMA(const std::string& name, int sample) OVERRIDE;
+  bool SendSparseToUMA(const std::string& name, int sample) override;
 
   // Sends a user action to Chrome for transport to UMA and returns true on
   // success. This method results in the equivalent of an asynchronous
@@ -96,7 +94,7 @@ class MetricsLibrary : public MetricsLibraryInterface {
   // chrome/browser/chromeos/external_metrics.cc.
   //
   // |action| is the user-generated event (e.g., "MuteKeyPressed").
-  virtual bool SendUserActionToUMA(const std::string& action) OVERRIDE;
+  bool SendUserActionToUMA(const std::string& action) override;
 
   // Sends a signal to UMA that a crash of the given |crash_kind|
   // has occurred.  Used by UMA to generate stability statistics.

metrics/persistent_integer_test.cc

@@ -16,12 +16,12 @@ const char kBackingFilePattern[] = "*.pibakf";
 using chromeos_metrics::PersistentInteger;
 
 class PersistentIntegerTest : public testing::Test {
-  virtual void SetUp() OVERRIDE {
+  void SetUp() override {
     // Set testing mode.
     chromeos_metrics::PersistentInteger::SetTestingMode(true);
   }
 
-  virtual void TearDown() OVERRIDE {
+  void TearDown() override {
     // Remove backing files.  The convention is that they all end in ".pibakf".
     base::FileEnumerator f_enum(base::FilePath("."),
                                 false,

metrics/uploader/curl_sender.h

@@ -17,8 +17,7 @@ class CurlSender : public Sender {
 
   // Sends |content| whose SHA1 hash is |hash| to server_url with a synchronous
   // POST request to server_url.
-  virtual bool Send(const std::string& content,
-                    const std::string& hash) OVERRIDE;
+  bool Send(const std::string& content, const std::string& hash) override;
 
   // Static callback required by curl to retrieve the response data.
   //

metrics/uploader/mock/mock_system_profile_setter.h

@@ -14,7 +14,7 @@ class ChromeUserMetricsExtension;
 // Mock profile setter used for testing.
 class MockSystemProfileSetter : public SystemProfileSetter {
  public:
-  void Populate(metrics::ChromeUserMetricsExtension* profile_proto) OVERRIDE {}
+  void Populate(metrics::ChromeUserMetricsExtension* profile_proto) override {}
 };
 
 #endif  // METRICS_UPLOADER_MOCK_MOCK_SYSTEM_PROFILE_SETTER_H_

metrics/uploader/mock/sender_mock.h

@@ -15,7 +15,7 @@ class SenderMock : public Sender {
  public:
   SenderMock();
 
-  bool Send(const std::string& content, const std::string& hash) OVERRIDE;
+  bool Send(const std::string& content, const std::string& hash) override;
   void Reset();
 
   bool is_good_proto() { return is_good_proto_; }

metrics/uploader/system_profile_cache.h

@@ -39,7 +39,7 @@ class SystemProfileCache : public SystemProfileSetter {
   SystemProfileCache();
 
   // Populates the ProfileSystem protobuf with system information.
-  void Populate(metrics::ChromeUserMetricsExtension* profile_proto) OVERRIDE;
+  void Populate(metrics::ChromeUserMetricsExtension* profile_proto) override;
 
   // Converts a string representation of the channel (|channel|-channel) to a
   // SystemProfileProto_Channel

metrics/uploader/upload_service.h

@@ -74,10 +74,10 @@ class UploadService : public base::HistogramFlattener {
   // Implements inconsistency detection to match HistogramFlattener's
   // interface.
   void InconsistencyDetected(
-      base::HistogramBase::Inconsistency problem) OVERRIDE {}
+      base::HistogramBase::Inconsistency problem) override {}
   void UniqueInconsistencyDetected(
-      base::HistogramBase::Inconsistency problem) OVERRIDE {}
-  void InconsistencyDetectedInLoggedCount(int amount) OVERRIDE {}
+      base::HistogramBase::Inconsistency problem) override {}
+  void InconsistencyDetectedInLoggedCount(int amount) override {}
 
  private:
   friend class UploadServiceTest;
@@ -117,7 +117,7 @@ class UploadService : public base::HistogramFlattener {
 
   // Callback for HistogramSnapshotManager to store the histograms.
   void RecordDelta(const base::HistogramBase& histogram,
-                   const base::HistogramSamples& snapshot) OVERRIDE;
+                   const base::HistogramSamples& snapshot) override;
 
   // Compiles all the samples received into a single protobuf and adds all
   // system information.