Implement CPU feature detection for ARM Linux.

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 0ae941761d1af59f94346d5a6314d79de61f7f2b..5182363a67a217f7d5bef954031b738a63c78240 100644
--- a/webrtc/system_wrappers/system_wrappers.gyp
+++ b/webrtc/system_wrappers/system_wrappers.gyp
@@ -123,6 +123,9 @@
           'defines': [
             'WEBRTC_THREAD_RR',
           ],
+          'dependencies': [
+            'cpu_features_webrtc.gyp:cpu_features_linux',

[kjellander_webrtc, 2016/03/30 19:11:17]

I'm not sure if this will compile fine with Chromium.
Would it be possible for you to create a Chromium checkout and compile Chromium
for regular Linux x86 and Linux ARM with this patch applied to
src/third_party/webrtc?
Notice you'll have to cut away one directory level when applying a patch into
that location since it's only mapping the webrtc/ subdirectory of the standalone
WebRTC repo.

+          ],
           'link_settings': {
             'libraries': [ '-lrt', ],
           },