Roll chromium_revision e144d30..6fdb142 (318658:318841) + remove OVERRIDE macro

Clang version changed 223108:230914
Details: https://chromium.googlesource.com/chromium/src/+/e144d30..6fdb142/tools/clang/scripts/update.sh

Removes the OVERRIDE macro defined in:
* webrtc/base/common.h
* webrtc/typedefs.h

The majority of the source changes were done by running this in src/:
perl -0pi -e "s/virtual\s([^({;]*(\([^({;]*\)[^({;]*))(OVERRIDE|override)/\1override/sg" `find {talk,webrtc} -name "*.h"  -o -name "*.cc*" -o -name "*.mm*"`

which converted all:
virtual Foo() OVERRIDE
functions to:
Foo() override

Then I manually edited:
* talk/media/webrtc/fakewebrtccommon.h
* webrtc/test/fake_common.h

Remaining uses of OVERRIDE was fixed by search+replace.

Manual edits were done to fix virtual destructors that were
overriding inherited ones.

Finally a build error related to the pure virtual definitions of
Read, Write and Rewind in common_types.h required a bit of
refactoring in:
* webrtc/common_types.cc
* webrtc/common_types.h
* webrtc/system_wrappers/interface/file_wrapper.h
* webrtc/system_wrappers/source/file_impl.cc

This roll should make it possible for us to finally re-enable deadlock
detection for TSan on the buildbots.

BUG=4106
R=pbos@webrtc.org, tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/41069004

Cr-Commit-Position: refs/heads/master@{#8596}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8596 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/talk/app/webrtc/remoteaudiosource.h b/talk/app/webrtc/remoteaudiosource.h
index b05ed3d..e49aca5 100644
--- a/talk/app/webrtc/remoteaudiosource.h
+++ b/talk/app/webrtc/remoteaudiosource.h
@@ -51,12 +51,12 @@
   typedef std::list<AudioObserver*> AudioObserverList;
 
   // MediaSourceInterface implementation.
-  virtual MediaSourceInterface::SourceState state() const OVERRIDE;
+  MediaSourceInterface::SourceState state() const override;
 
   // AudioSourceInterface implementation.
-  virtual void SetVolume(double volume) OVERRIDE;
-  virtual void RegisterAudioObserver(AudioObserver* observer) OVERRIDE;
-  virtual void UnregisterAudioObserver(AudioObserver* observer) OVERRIDE;
+  void SetVolume(double volume) override;
+  void RegisterAudioObserver(AudioObserver* observer) override;
+  void UnregisterAudioObserver(AudioObserver* observer) override;
 
   AudioObserverList audio_observers_;
 };