Merge media::ScreenCaptureDeviceCore into ScreenCaptureMachineAndroid.

With no other screen capture implementations dependent upon
media::ScreenCaptureDeviceCore, ThreadSafeCaptureOracle, etc.; this
change merges this code into ScreenCaptureMachineAndroid. Unused
functionality has been stripped-out, and minor callpoint- and lint-
related clean-ups were made. No behavior/functional changes.

Testing: Built monochrome_public_apk, installed it to my phone, and
confirmed Android screen capture from that Chromium build still works by
running a demo app: https://paulkinlan.github.io/screenrecord/.

Bug: 806366,487935
Change-Id: I3edb2603261b6ed60e31edf795ac8da9a2a8525c
Reviewed-on: https://chromium-review.googlesource.com/1137733
Commit-Queue: Yuri Wiitala <miu@chromium.org>
Reviewed-by: Weiyong Yao <braveyao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575864}
10 files changed