[usecase-webapi][XWALK-2270] Fix bug for MediaRenderer

- Add Precondition for the test
- Failure analysis: Cannot play video

Impacted tests(approved): new 0, update 1, delete 0
Unit test platform: [Tizen IVI]
Unit test result summary: pass 0, fail 1, block 0
[webapi] Fix interface name for WebRTC

- Fix interface name
- Failure analysis: The ondatachannel event, onidpvalidationerror event and onidentityresult event cannot be fired. The Identity API extends the RTCPeerConnection interface is not support.

Impacted tests(approved): new 0, update 143, delete 0
Unit test platform: [Tizen IVI]
Unit test result summary: pass 111, fail 15, block 17
[webapi] Update 44 TCs for MediaRenderer

- Update 44 TCs for MediaRenderer
- Failure analysis: The statuschanged event and rendererlost event cannot be fired

Impacted tests(approved): new 0, update 44, delete 0
Unit test platform: [Tizen IVI]
Unit test result summary: pass 34, fail 4, block 6
[wrt][XWALK-2029]Update DB name

Detailed commit message (if have)]
Impacted TCs num(approved): New 0, update 4, deleted 0
Unit test platform: [tizen]
Unit test result summary: Pass 4 , Fail 0, Blocked 0

wrt-manifest-tizen-tests: PASS 390,Fail 0
[embedding][XWALK-1052] Leverage developer's sample tests for extension.

- Add extension support for embedding API.

Impacted tests(designed|approved): new 1, update 0, delete 0
Unit test platform: [Android]
Unit test result summary: pass 1, fail 0, block 0
[usecase-webapi]Update usecase for gamepad

- Use sample app from https://github.com/InternetExplorer/Gamepad-Sample to replace the existing usecase.
- Fail Reason: the gamepad can not connect to the android device, but this sample is passed in chrome 37.

Impacted TCs num: New 0, Update 1, Delete 0
Unit test Platform: Andriod
Unit test result summary: Pass 0, Fail 1, Blocked 0
[usecase-webapi] Fix the bug that the 'Pass' button is disabled when click the 'Cancle CSS FullScreen' button.

Impacted tests(approved): New 0, Update 1, Delete 0
Unit test platform: [TIZEN IVI]
Unit test result summary: Pass 1, Fail 0, Block 0
[webapi]Change ref test in tct-flexiblebox-css3-tests

- Add 2 reference files for 19 tests
- Still keep the 19 ref tests as manual because test tool haven't support ref type

Impacted tests(approved): new 0, update 19, delete 0
Unit test platform: [Tizen IVI]
Unit test result summary: pass 19, fail 0, block 0
[misc-cordova][xwalk-2289] Update cordova usecase description
Merge pull request #688 from linshen/shenlin/wrt/sqlite3

[wrt][XWALK-2029]Update DB name
Merge pull request #674 from wanghongjuan/wanghongjuan/misc/cordova-fix

[misc-cordova][xwalk-2289] Update cordova usecase description
Merge pull request #698 from JianfengXu/xujf/gamepad/usecase/update

[usecase-webapi]Update usecase for gamepad
Merge pull request #680 from yunxliu/yunxliu/webapi/webrtc_modify

[webapi] Fix interface name for WebRTC
Merge pull request #683 from yunxliu/yunxliu/misc/mediaRenderer_modify

[usecase-webapi][XWALK-2270] Fix bug for MediaRenderer
Merge pull request #684 from yunxliu/yunxliu/webapi/mediaRenderer_update

[webapi] Update 44 TCs for MediaRenderer
[wrt]update test.py to run on list devices

[Detailed commit message (if have)]
Impacted TCs num(approved): New: 131
Unit test platform: [tizen]
Unit test result summary: Pass 131 , Fail 0, Blocked 0
Merge pull request #706 from linshen/shenlin/manifest-auto

[wrt]update test.py to run on list devices
[usecase-webapi][XWALK-1473] Fix bug for WebRTC

- The onDataChannel can not be fired on the first channel inChrom, so avoid to use it

Impacted tests(approved): new 0, update 1, delete 0
Unit test platform: [Android]
Unit test result summary: pass 1, fail 0, block 0
[webapi-usecase] Intergation of all subcases to one page for CSSStyleAttribute

- Fail Reason:[XWALK-1326]

Impacted TCs num: New 0, Update 1, Delete 0
Unit test Platform: [Andriod]
Unit test result summary: Pass 0, Fail 1, Blocked 0
Merge pull request #704 from chenxix/chenxi/misc-uiautomation/css-flex

[webapi]Change ref test in tct-flexiblebox-css3-tests