More debugging code for RootWindow holding onto deleted aura::Window

Real changes:
. Streamline resetting of mouse_moved_handler_. Changes to *always*
  reset if mouse_moved_handler_ is not a child of this. This ensures
  we always clean up mouse_moved_handler_ if things shifted from when
  we set mouse_moved_handler_.
. Moves clearing *before* invoking OnCaptureLost. This way if
  OnCaptureLost has side effects we aren't left in a bad state.

And MouseMovedHandlerSetReason into debugging class. I'm getting
crashes in OnWindowDestroyed but can't see the reason. This should fix
that (assuming I still get crashes).

BUG=275760
TEST=none
R=sadrul@chromium.org

Review URL: https://codereview.chromium.org/25302002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226164 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226164
PPAPI: Remove instance param from GetFileTaskRunner

BUG=

Review URL: https://codereview.chromium.org/25328002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226165 0039d316-1c4b-4281-b951-d872f2087c98
Fix redundant media source seek suppression optimization on Chrome for Android

Fix the MSE case of seek(1) + seek(2) + seek(1), where we cannot
simply collapse these to just seek(1) because the ChunkDemuxer is
expecting seek(2) that never occurs and would result in persistent
kAborted buffers until next seek.

BUG=267111
R=acolwell@chromium.org,qinmin@chromium.org
TEST=Local device logs confirm frequent redundant alternating pending MSE seeks are no longer suppressed, and all StartWaitingForSeek() calls with intervening CancelPendingSeek() call(s) are for the most recent CancelPendingSeek() call's time.

Review URL: https://codereview.chromium.org/25380002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226166 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226165
SVN changes up to revision 226166
cros: Fix keyboard overlay labels for monitor mirroring/swap primary

The keys were mislabeled in the master spreadsheet as a side effect of
F4 being renamed from maximize to full screen.  Fixed the spreadsheet too.

BUG=267886
TEST=Press Ctrl-Alt-/, hold down Ctrl, verify F4 says "Mirror display", hold down Alt, verify F4 says "Swap primary monitor"
NOTRY=true

Review URL: https://codereview.chromium.org/25384003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226167 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226167