Attempt to re-land FocusManager removal from Aura.

content_browsertests ContentWindowReparent test was failing, presumably because a focus notification wasn't being broadcast by the new test focus client.

R=sky@chromium.org
BUG=

Review URL: https://codereview.chromium.org/29883002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229480 0039d316-1c4b-4281-b951-d872f2087c98
Teach mojo_shell how to load http URLs

After this CL, we can load content over HTTP. In order to make
that work, I needed to introduce a number of basic concepts
into the shell, including an IO thread and a directory to
store data (such as the HTTP cache).

I've tried to keep the net dependencies separated from the
bulk of the mojo_shell code because I expect we'll want to
move the net dependencies to an app that runs on top of the
Mojo platform rather than linked into the mojo_shell itself.
To that end, the mojo::loader::Loader class doesn't leak any
net headers to its clients.

The version of the loader in this CL is extremely basic. We'll
undoubtedly make it fancier as time goes on. The next step
after this CL is to store the result in a file and then load
that file as a shared object.

R=aa@chromium.org, darin@chromium.org

Review URL: https://codereview.chromium.org/27943002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229481 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229481
Update the text on the chrome://downloads warning confirmation

This changes the text on the chrome://downloads confirmation for known malware.

BUG=305387
R=asanka@chromium.org

Review URL: https://codereview.chromium.org/27761002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229482 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229482