Invoke LeakSanitizer in BrowserProcessImpl::ReleaseModule().

Leak detection is normally invoked from an AtExit handler which runs very late
in the shutdown process. This doesn't play well with Chrome, because memory is
often intentionally leaked during shutdown, causing a flood of uninteresting
leak reports. Instead we try to invoke leak detection at the earliest possible
point in the shutdown process.

BUG=307043
R=glider@chromium.org, thestig@chromium.org

Review URL: https://codereview.chromium.org/26895007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228621 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228621