[rAc OSX] Factor out AutofillHeader class to contain dialog header elements.

Currently contains the title and the account chooser.  In the next CL, I'm
planning to move notifications into the header as well.

BUG=315977
TEST=none
R=groby@chromium.org

Review URL: https://codereview.chromium.org/77283002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236997 0039d316-1c4b-4281-b951-d872f2087c98
google_apis: Random fix in task_util.h

Change RunTaskOnThread's argument type from MessageLoopProxy to SingleThreadTaskRunner in favor of generality
Move CreateErrorRunCallback to its exclusive user job_scheduler.cc

BUG=None
TEST=unit_tests

Review URL: https://codereview.chromium.org/77553006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236998 0039d316-1c4b-4281-b951-d872f2087c98
[Mojo] Improve JavaScript API for MojoReadMessage

Originally, I tried to make the JavaScript bindings for the core Mojo APIs a
literal translation of the C APIs, but that makes MojoReadMessage a bit awkward
because C needs to worry much more about buffer allocation than JavaScript. In
building towards using the hello_world_service, I found that it was much easier
to push the MojoReadMessage pattern from connector.cc into C++ and make the
JavaScript API a bit more idiomatic by just returning an ArrayBuffer for the
message and an Array of handles.

BUG=317398

Review URL: https://codereview.chromium.org/83143002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236999 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236998
SVN changes up to revision 236999