Fix crash when using asynchronous continuation with a custom resource handler (issue #1066).

git-svn-id: http://chromiumembedded.googlecode.com/svn/trunk/cef3@1579 5089003a-bbd8-11dd-ad1f-f1f9622dbc98
- Add MayBlock() method to stream classes which is used as a hint when determining the thread to access the stream from (issue #1187).
- In cases where MayBlock() returns true have CefStreamResourceReader perform the reads on the FILE thread (issue #1187).

git-svn-id: http://chromiumembedded.googlecode.com/svn/trunk/cef3@1582 5089003a-bbd8-11dd-ad1f-f1f9622dbc98
Revert unintended changes from revision 1582.

git-svn-id: http://chromiumembedded.googlecode.com/svn/trunk/cef3@1583 5089003a-bbd8-11dd-ad1f-f1f9622dbc98
Revert unintended changes from revision 1582.

git-svn-id: http://chromiumembedded.googlecode.com/svn/trunk/cef3@1584 5089003a-bbd8-11dd-ad1f-f1f9622dbc98
Mac: Fix compile errors.

git-svn-id: http://chromiumembedded.googlecode.com/svn/trunk/cef3@1591 5089003a-bbd8-11dd-ad1f-f1f9622dbc98