[Android] Add the test case about DomStorageEnabled and AppCacheEnabled.

Implement the test cases about DomStorageEnabled and AppCacheEnabled.

Test AppCache by setting the data in TestWebServer instance.
Test DomStorage by loading the html, in this html file, it checks
the domstorage enabled or not by javascript.

For test case "DomStorageEnabled" should add the parameter "--test_data", as follows:
build/android/run_instrumentation_tests.py --test-apk XWalkCoreTest \
--test_data xwalkview:xwalk/test/data/device_files/ \
--verbose -I --num_retries=1 -f testDomStorageEnabledWithTwoViews
[Android][SysApps] Support 'onxxx' event handler for display and storage

This commit fixes two things:
1. The type name in the addEventListener() should be 'attach' instead of
'onattach' according to the W3C spec. Same as 'detach', 'connect' and 'disconnect'.
2. Support 'onxxx' event handler, for example:
navigator.system.onattach = function() {...}
Merge pull request #1108 from fyraimar/new_add_listener_method

[Android][SysApps] Support 'onxxx' event handler for display and storage
[Android] Enable the internal extension in the embedded mode.

Copy the js wrapper into the xwalk_app_template target, which
would be used by the web app when packaged in embedded mode.

BUG=https://crosswalk-project.org/jira/browse/XWALK-615
[Android] Implement the native http authentication in xwalk runtime.

  Native http authentication has to be handled in xwalk runtime for Android
port. It is used to provide the xwalk login delegation and handle the http
authentication request. This fix is to provide the native xwalk login delegation
and set up the bridge between the native http authentication handler and corresponding
handler in runtime core java layer.

BUG=https://crosswalk-project.org/jira/browse/XWALK-159
[Android][SysApps] Implement W3C Audio/Video codecs API for Android 4.1 and above

The current implementation relies on the MediaCodec class introduced
since Android 4.1 (API Level 16), as a result, an abstract class XWalkMediaCodec
is added to allow this API run on the older Android but will empty list.

The support for 4.0 (API level == 15) will be added in another PR.

SPEC=http://www.w3.org/2012/sysapps/device-capabilities/
BUG=https://crosswalk-project.org/jira/browse/XWALK-48
Merge pull request #1175 from fyraimar/impl_codec

[Android][SysApps] Implement W3C Audio/Video codecs API for Android 4.1 and above
Merge pull request #584 from wuhengzhi/domstorage

[Android] Add the test case about DomStorageEnabled and AppCacheEnabled.
Merge pull request #1135 from ShDavidliu/http_auth

[Android] Implement the native http authentication in xwalk runtime.
Merge pull request #1232 from junmin-zhu/internalAPI

[Android] Enable the internal extension in the embedded mode.