Add a default implementation in metrics_default.cc of histograms methods in system_wrappers/interfac

webrtc/media/media.gyp

Index: webrtc/media/media.gyp
diff --git a/webrtc/media/media.gyp b/webrtc/media/media.gyp
index 230d33ab38f0c30d6d09f4c3fb3a55b1c2c28fa5..b880f93d15c6cc8d06c23e02f01d850144078ef0 100644
--- a/webrtc/media/media.gyp
+++ b/webrtc/media/media.gyp
@@ -17,7 +17,6 @@
         '<(webrtc_root)/common.gyp:webrtc_common',
         '<(webrtc_root)/webrtc.gyp:webrtc',
         '<(webrtc_root)/voice_engine/voice_engine.gyp:voice_engine',
-        '<(webrtc_root)/system_wrappers/system_wrappers.gyp:metrics_default',
         '<(webrtc_root)/system_wrappers/system_wrappers.gyp:system_wrappers',
         '<(webrtc_root)/libjingle/xmllite/xmllite.gyp:rtc_xmllite',
         '<(webrtc_root)/libjingle/xmpp/xmpp.gyp:rtc_xmpp',
@@ -214,6 +213,11 @@
             ['build_libyuv==1', {
               'dependencies': ['<(DEPTH)/third_party/libyuv/libyuv.gyp:libyuv',],
             }],
+            ['OS!="android"', {
+              'dependencies': [
+                '<(webrtc_root)/system_wrappers/system_wrappers.gyp:metrics_default',
+              ],
+            }],
             ['OS=="ios"', {
               # TODO(kjellander): Make the code compile without disabling these.
               # See https://bugs.chromium.org/p/webrtc/issues/detail?id=3307
@@ -260,6 +264,7 @@
           'dependencies': [
             '<(webrtc_root)/base/base_tests.gyp:rtc_base_tests_utils',
             '<(webrtc_root)/media/media.gyp:rtc_media',
+            '<(webrtc_root)/system_wrappers/system_wrappers.gyp:metrics_default',
             'rtc_unittest_main',
           ],
           'sources': [