Use cpu_features library from ndk when built with chromium.

In Chromium on Andorid, nkd provides cpu_features library so that all modules using that library can link against it to avoid function re-definition.
Review URL: https://webrtc-codereview.appspot.com/937024

git-svn-id: http://webrtc.googlecode.com/svn/trunk@3127 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/system_wrappers/source/cpu_features_android.c b/webrtc/system_wrappers/source/cpu_features_android.c
index 7a4fa6e..8f5e3ea 100644
--- a/webrtc/system_wrappers/source/cpu_features_android.c
+++ b/webrtc/system_wrappers/source/cpu_features_android.c
@@ -8,7 +8,11 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+#if defined(WEBRTC_CHROMIUM_BUILD)
+#include <cpu-features.h>
+#else
 #include "android/cpu-features.h"
+#endif  //  defined(WEBRTC_CHROMIUM_BUILD)
 
 uint64_t WebRtc_GetCPUFeaturesARM(void) {
   return android_getCpuFeatures();