base: add MockTimer

MockTimer is a subclass of Timer that will never fire on its own, but can be
manually fired by a test with the Fire() method.

BUG=131227

Review URL: https://codereview.chromium.org/197243003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256942 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256942
Ensure that SandboxProcessLauncherDelegates are deleted

Fix to ChildProcessLauncher::LaunchInternal

TBR=jam@chromium.org
BUG=none

Review URL: https://codereview.chromium.org/199333004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256943 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256943