Expose WebInputEvent::Type string conversion with WebInputEventTraits

Move the WebInputEvent::Type to string conversion code from RenderWidget to
WebInputEventTraits. This is particularly useful for event tracing at various
stages of the input pipeline.

Review URL: https://codereview.chromium.org/27336003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228951 0039d316-1c4b-4281-b951-d872f2087c98
Copy ldb files in ChromiumEnv for the purpose of backups.

If it is later detected that an ldb file has gone missing it
will be restored from its backup.

BUG=239999
R=isherman@chromium.org, jsbell@chromium.org

Review URL: https://codereview.chromium.org/27022005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228952 0039d316-1c4b-4281-b951-d872f2087c98
Small cleanup following discussion on https://codereview.chromium.org/27273004/

TBR=bauerb

Review URL: https://codereview.chromium.org/27517003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228953 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228951
SVN changes up to revision 228953