[Android] Enable remote debugging after rebase to M39

Adjust classes according upstream changes of DevToolsManagerDelegate
and DevToolsHttpHandlerDelegate.
Besides, hardcode webkit revision to generate remote frontend url
due to https://code.google.com/p/chromium/issues/detail?id=425912
https://code.google.com/p/chromium/issues/detail?id=425912 already fixed (duplicated as https://code.google.com/p/chromium/issues/detail?id=425155),  so we can merge the fix (https://src.chromium.org/viewvc/blink?view=rev&revision=182816) instead of hard-coding