Bug 881137 - Support hdpi resolution device.
Bug 893310 - hdpi/xhdpi replacing @1.5x images assets for Gallery app
Bug 893023 - Replace assets
Merge pull request #10956 from cctuan/hd-gallery

Bug 893310 - hdpi/xhdpi replacing @1.5x images assets for Gallery app, r=timdream
Merge pull request #10768 from evanxd/bug-881137-v1.1.0hd

Bug 881137 - hdpi/xhdpi resolution assets and layout for Calendar app
Merge pull request #10958 from crh0716/1.1hd/893023

Bug 893023 - Replace assets r=rexboy, a=hd+
Bug 893694 - Update the 1.5x version of images.
Bug 881149 -  hdpi/xhdpi resolution layout for Homescreen app
     1. adjust to show 4 x 5 grid on WVGA.
     2. modify the scale ratio of app icon according to
        window.devicePixelRatio.
     3. Add 1.5x graphics (not complete, some assets are still missing)
Merge pull request #10947 from RudyLu/homescreen/v1.1.0hd

Bug 881149 - hdpi/xhdpi resolution assets and layout for Homescreen app. 
  r=crdlc. a=hd+.
Merge pull request #10971 from evanxd/bug-893694-v1.1.0hd

Bug 893694 - Bug 893694 - [Calendar] Update the 1.5x version of images for Calendar App
Bug 891277 - Update Usage assets, r=me
Bug 893710 - hdpi resolution tweaks for System app
Merge pull request #11004 from cctuan/hd-893710

Bug 893710 - hdpi resolution tweaks for System app
Bug 894239 - [Clock] Update icon which be provide via UX team for assets @1.5
Merge pull request #11000 from ian-liu/v110hd/clock/Bug894239_Update_icon_which_be_provide_via_UX_team_for_assets_@1.5

V110hd/clock/bug894239 update icon which be provide via ux team for assets @1.5, r=@rexboy7
Bug 891807 - @1.5x assets are required for system app