[Android]Implement DevTools protocol /json/activate/.

BUG=XWALK-2228.
Add license header to lint.py and utils.py in tools

BUG=XWALK-194
Merge pull request #2294 from wang16/add_license

Add license header to lint.py and utils.py in tools
Fix Mac build : Complex classes needs out of line destructors and constructors.
Merge pull request #2282 from iKevinHan/xwalk-2228

[Android]Implement DevTools protocol /json/activate/.
[Android] Adjust XWalkPermissionClient::allowImage's signature.

The parent method's signature changed in Chromium r170983.
[Android] Adjust XWalkRenderViewExt::DidCommitProvisionalLoad's signature.

The parent method's signature changed in r261764.
[Android] Adjust RuntimeResourceDispatcherHostDelegateAndroid::HandleExternalProtocol's signature.

The parent method's signature changed in r261014.
[Android] Rename XWalkRenderViewHostExt::RenderViewGone.

The method was renamed to RenderProcessGone upstream in r210727 more
than a year ago.
Merge pull request #2301 from rakuco/android-method-signatures

[Android] Fix the signature of several methods.
Merge pull request #2300 from darktears/master

Fix Mac build : Complex classes needs out of line destructors and constr...