Make it possible to build webrtc for arm64.

- Bump revision of protobuf lib
- Remove -Wextra for arm64 gcc targets (warnings in stlport)
- Add MemoryBarrier implementation in single_rw_fifo.cc.
- [pending 15619004]: Bump revision of /deps/tools/android to get md5sum_bin for arm64.

BUG=chromium:354405,chromium:354539
R=andrew@webrtc.org, fischman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/15629004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6330 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/DEPS b/DEPS
index f1b0cad..f10a5dd 100644
--- a/DEPS
+++ b/DEPS
@@ -108,7 +108,7 @@
     Var("chromium_trunk") + "/deps/third_party/opus@256783",
 
   "third_party/protobuf":
-    Var("chromium_trunk") + "/src/third_party/protobuf@251211",
+    Var("chromium_trunk") + "/src/third_party/protobuf@" + Var("chromium_revision"),
 
   "third_party/sqlite/":
     Var("chromium_trunk") + "/src/third_party/sqlite@" + Var("chromium_revision"),
@@ -205,7 +205,7 @@
     # Precompiled tools needed for Android test execution. Needed since we can't
     # compile them from source in WebRTC since they depend on Chromium's base.
     "tools/android":
-      (Var("googlecode_url") % "webrtc") + "/deps/tools/android@4258",
+      (Var("googlecode_url") % "webrtc") + "/deps/tools/android@6306",
 
     "third_party/android_tools":
       From("chromium_deps", "src/third_party/android_tools"),