Remove non-monotonic clock support

webrtc/system_wrappers/system_wrappers.gyp

Index: webrtc/system_wrappers/system_wrappers.gyp
diff --git a/webrtc/system_wrappers/system_wrappers.gyp b/webrtc/system_wrappers/system_wrappers.gyp
index bce91000fc9289f69a966d28600b770e529af2ee..5250d3400e8dd2b96da1f32d6b8174eb893f4211 100644
--- a/webrtc/system_wrappers/system_wrappers.gyp
+++ b/webrtc/system_wrappers/system_wrappers.gyp
@@ -98,11 +98,6 @@
         ['OS=="android"', {
           'defines': [
             'WEBRTC_THREAD_RR',
-            # TODO(leozwang): Investigate CLOCK_REALTIME and CLOCK_MONOTONIC
-            # support on Android. Keep WEBRTC_CLOCK_TYPE_REALTIME for now,
-            # remove it after I verify that CLOCK_MONOTONIC is fully functional
-            # with condition and event functions in system_wrappers.
-            'WEBRTC_CLOCK_TYPE_REALTIME',
            ],
           'conditions': [
             ['build_with_chromium==1', {
@@ -129,9 +124,6 @@
         ['OS=="linux"', {
           'defines': [
             'WEBRTC_THREAD_RR',
-            # TODO(andrew): can we select this automatically?
-            # Define this if the Linux system does not support CLOCK_MONOTONIC.
-            #'WEBRTC_CLOCK_TYPE_REALTIME',
           ],
           'link_settings': {
             'libraries': [ '-lrt', ],
@@ -148,7 +140,6 @@
         ['OS=="ios" or OS=="mac"', {
           'defines': [
             'WEBRTC_THREAD_RR',
-            'WEBRTC_CLOCK_TYPE_REALTIME',
           ],
         }],
         ['OS=="win"', {