GitLab

    
This removes the use of memory pressure signals from discardable memory
system and instead introduces an explicit call for reducing emulated
discardable memory that the renderer can call when all widgets are hidden
until we have a better mechanism in place.
    
BUG=398087
TEST=base_unittests,content_browsertests

Review URL: https://codereview.chromium.org/448173002

Cr-Commit-Position: refs/heads/master@{#289127}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289127 0039d316-1c4b-4281-b951-d872f2087c98