Make ImageView drawable update more efficient in some cases.

When updating the view's drawable via setImageResource or setImageURI,
make sure to skip the layout pass if the old and new drawable have equal
sizes. This follows what is already done for setDrawable().

Change-Id: If73d225e38d0a2f7c616c4aeb33f67bdaed390f1
DownloadManager: add to pause/resume download by user

We add pause and resume APIs here to make application can
pause and resume downloads by DownloadManager.

Code change contains:
  - add pause and resume download APIs.
  - add another paused status for this case.

Change-Id: I5bf4f15b2464009595f7926522ca6d5f1b0e2b8d
BootReceiver: Skip subdirectories inside tombstones scan

Properly handle (vendor-specific) subdirs under tombstones
directory by skipping over them.

CRs-Fixed: 407529
Change-Id: I0cecd9fa629fad35d62d508ddaf13968c2e46f93
SystemUI: Add emergency call button in lock screen

Add emergency call button in swipe lock interface.
Update emergency call button after inflating bottom area view
and configuration changes.

CRs-Fixed: 736263

Change-Id: I7d4090da74e164647dd3ab927c40398de0f40a92
SystemUI: Update cast tile when wifi display status changes

Cast tile in quick setting does not watch for wifi display status changes.
As a result, it will not update when wifi display status changes.

Register a broadcast to watch for wifi display status changes as settings
and update remote displays when wifi display status changes.

CRs-Fixed: 718032

Change-Id: Ib2ca4677be91817c007db941531849bbc7eff5d3