[Image Capture] Add focusDistance constraint. This CL adds focusDistance to ImageCapture API. This was added to the spec in https://github.com/w3c/mediacapture-image/pull/175 Layout tests and mock tests are updated to support the same. Support for Android is added. TEST= run the demo in https://codepen.io/rijuB/pen/NzWpxG use slider to change focusDistance. BUG=732807 Intent to Implement and Ship discussions: https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/oNxzXaFY9c8 Change-Id: I9b7cbf3c85fd35741a8c7ed229910a996e14ee8f Reviewed-on: https://chromium-review.googlesource.com/1124839 Reviewed-by: Miguel Casas <mcasas@chromium.org> Reviewed-by: Kinuko Yasuda <kinuko@chromium.org> Reviewed-by: Guido Urdaneta <guidou@chromium.org> Commit-Queue: Rijubrata Bhaumik <rijubrata.bhaumik@intel.com> Cr-Commit-Position: refs/heads/master@{#588299} 
diff --git a/mediacapture-image/MediaStreamTrack-applyConstraints-getSettings.html b/mediacapture-image/MediaStreamTrack-applyConstraints-getSettings.html index 6241d59..1a1b58e 100644 --- a/mediacapture-image/MediaStreamTrack-applyConstraints-getSettings.html +++ b/mediacapture-image/MediaStreamTrack-applyConstraints-getSettings.html 
@@ -31,6 +31,7 @@  contrast : 4,  saturation : 5,  sharpness : 6, + focusDistance : 7,    zoom : 3.141592,   @@ -82,6 +83,8 @@  assert_equals(constraints.advanced[0].sharpness, settings.sharpness,  'sharpness');   + assert_equals(constraints.advanced[0].focusDistance, settings.focusDistance, + 'focusDistance');  assert_equals(constraints.advanced[0].zoom, settings.zoom, 'zoom');    assert_equals(constraints.advanced[0].torch, settings.torch, 'torch');