[Android] Disable hw encoding/decoding acceleration for WebRTC

The flag hw encoding/decoding acceleration for WebRTC is enabled by
default, it is controlled through GPU black list, please see:
https://chromiumcodereview.appspot.com/10832356/
But crosswalk is ignoring GPU black list because of enabling WebGL.

Currently, it is also disabled on chrome for Android M31, more information
please see: http://code.google.com/p/chromium/issues/detail?id=305421

BUG=https://crosswalk-project.org/jira/browse/XWALK-41
[Windows] Enable aura on Windows

The origin MACRO protection for XWalkViewsDelegate
is "#if !defined(OS_WIN) && defined(USE_AURA)", which
is not appropriate on Windows after Windows build also
switches to use aura.

Change the condition to "#if defined(USE_AURA)" and
implement the missing abstract function on Windows.
[Android] Add Java extension system files to xwalk core library project.

As extensions are required by apps that developed based on xwalk core
library, the files of Java extension system should be added to the tree
of xwalk core library project.
Bump version to 2.31.25.0
Merge pull request #987 from wang16/windows_aura

[Windows] Enable aura on Windows
Bump version to 2.31.26.0
[Android] Add the instrumentation test for external extension.

This patch is to create two unit tests for external extensions for runtime
client. Since there are two modes - shared and embedded modes which are
supported in runtime client, here two copies here.

To avoid duplicated data, a shared directory is created to store data and
some code which should be used by all other instrumentation tests. So
we don't need to copy them everywhere. All testing data should be put
in here in future.

Besides, an external Java extension implementation is needed and
it has to be in test shell apks together with some assets and can't be in
instrumentation test apks because test shells can't access assets in
other assets.

For future, we should avoid duplicated code for embedded shell and shared
shell. This is a TODO.

BUG=#986
[Android] Fixes #979 - Changes in test pages won't rebuild XWalkCoreTest

With testing, if the files in 'sources' get updated (touch or content
change), the 'none' type target won't get rebuilt.

Instead, 'variable': {'additional_input_paths'} works as wish, that how
this commit comes.

BUG=#979
[WiDi API] First commit for Presentation API implementation on Android

This commit is the first patch to implement Presentation API spec on
Android. It is intended to bring wireless display support into Web. The
new API is placed under 'navigator.presentation' namespace, and the
'displayavailable' property and its change event is implemented in this
commit by use of DisplayManager in Android SDK.

SPEC=http://otcshare.github.io/presentation-spec/index.html
BUG=https://github.com/crosswalk-project/crosswalk/issues/577
Merge pull request #971 from yinli/webrtc_yinli

[Android] Disable hw encoding/decoding acceleration for WebRTC
Merge pull request #983 from gaochun/cordova_xwalk

[Android] Add Java extension system files to xwalk core library project.
Merge pull request #991 from halton/android_test_gyp

[Android] Fixes #979 - Changes in test pages won't rebuild XWalkCoreTest
Merge pull request #965 from hmin/widi-android-part1

[WiDi API] First commit for Presentation API implementation on Android
Merge pull request #988 from yongsheng/extensionunit

[Android] Add the instrumentation test for external extension.
[Android] Hotfix in Presentation API extension

This patch is to fix 2 issues:
o Place PresentationExtension into ..api.presentation package to follow
  the general pattern in Java. Otherwise, we will get error message when
  import xwalk_core_library into eclipse.
o Don't create PresentationExtension if failing to load the JS binding
  code from assets/

TODO:
1. Figure out why the external extension test crash when passing a empty string to
   create a new XWalkExtension.
2. Ensure the PresentationExtension code doesn't break Android 4.0 since
   DisplayManager is introduced since API level 17.
[Android] Fix the crash when running some WebAPI components

Root cause: The crash of these WebAPI test cases are all caused
by the failure to access the i10n strings loaded from pak file.
In shared apk mode, the pak should be loaded from the Library apk
instead of App apk, for which we should use the Context of Library
apk for ResourceExtractor(under Content layer) to extract the pak
file. But after rebasing to V31, ResourceExtractor gets the Context
by mContext.getApplicationContext, which results that it gets the
wrong Context of App apk.

Fix: Force to initilize Context of ResourceExtractor before the
browser process starts.

BUG=https://github.com/crosswalk-project/crosswalk/issues/941
[Android] local variable 'xpk_temp_dir' referenced before assignment.

In the exception catch code block, 'xpk_temp_dir' is used before assignment.
It would mislead the develper with wrong log. So assign 'xpk_temp_dir'
with empty string at the beginning to fix this issue.

BUG=https://github.com/crosswalk-project/crosswalk/issues/999
Merge pull request #1001 from junmin-zhu/xpk_dir

[Android] local variable 'xpk_temp_dir' referenced before assignment.
Merge pull request #1006 from hmin/hotfix

[Android] Hotfix in Presentation API extension
Merge pull request #1000 from xingnan/fix-crash

[Android] Fix the crash when running some WebAPI components