Adds MemoryPressureListener.

Some platforms, like android, send clear signals when
under memory pressure.
Create a centralized place so that:
- Underlying platform can advise the rest of the system of
its memory status.
- Individual subsystems can then listen to such notifications
and free their memory as per their own policies.

BUG=246125

Review URL: https://chromiumcodereview.appspot.com/15995014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@205796 0039d316-1c4b-4281-b951-d872f2087c98


CrOS-Libchrome-Original-Commit: 19d5769c94918d1416b83d3082c5d4ddfc901d1c
10 files changed
tree: a021c00dc8c85f4450eb72837d4aebe898914dd5
  1. base/
  2. build/
  3. dbus/
  4. ipc/
  5. testing/
  6. third_party/