Bug 881137 - Support hdpi resolution device.
Bug 881144 - Support hdpi resolution device.
Bug 881136 - hdpi/xhdpi resolution assets and layout for Browser app
Merge pull request #10502 from gasolin/browserhd

Bug 881136 - hdpi/xhdpi resolution assets and layout for Browser app, r=dale
Merge pull request #10912 from crh0716/1.1hd/881144

Bug 881144 - Support hdpi resolution device. r=dkuo, a=hd+
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 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)