Use floor instead of ceil for the size of the layer for wallpapers.
Use floor instead of ceil for the size of the layer for wallpapers.

Otherwise, pixels on the edge of wallpaper may be blended with the pixel outside of the boundary.

BUG=368591
R=mukai@chromium.org

Review URL: https://codereview.chromium.org/871773004

Cr-Commit-Position: refs/heads/master@{#313003}
(cherry picked from commit 8fab1bba6ba22e5a917d8afcc835ec385f59cb2e)

Review URL: https://codereview.chromium.org/911663004

Cr-Commit-Position: 665a5787e4610f1ec55d3a4e2f02ab0724e38987@{#247}
Cr-Branched-From: 4cd5f18d847990599feba509541d8a7b9a16883a@{#310958}

markYoungH/chromium.src,jaruba/chromium.src,M4sse/chromium.src,M4sse/chromium.src,mohamed--abdel-maksoud/chromium.src,M4sse/chromium.src,jaruba/chromium.src,M4sse/chromium.src,dushu1203/chromium.src,M4sse/chromium.src,mohamed--abdel-maksoud/chromium.src,mohamed--abdel-maksoud/chromium.src,dednal/chromium.src,dednal/chromium.src,markYoungH/chromium.src,jaruba/chromium.src,dushu1203/chromium.src,dednal/chromium.src,markYoungH/chromium.src,Jonekee/chromium.src,markYoungH/chromium.src,krieger-od/nwjs_chromium.src,krieger-od/nwjs_chromium.src,dushu1203/chromium.src,Jonekee/chromium.src,Jonekee/chromium.src,krieger-od/nwjs_chromium.src,krieger-od/nwjs_chromium.src,dednal/chromium.src,markYoungH/chromium.src,mohamed--abdel-maksoud/chromium.src,dushu1203/chromium.src,mohamed--abdel-maksoud/chromium.src,M4sse/chromium.src,markYoungH/chromium.src,dushu1203/chromium.src,dushu1203/chromium.src,Jonekee/chromium.src,mohamed--abdel-maksoud/chromium.src,M4sse/chromium.src,dednal/chromium.src,mohamed--abdel-maksoud/chromium.src,mohamed--abdel-maksoud/chromium.src,mohamed--abdel-maksoud/chromium.src,markYoungH/chromium.src,jaruba/chromium.src,jaruba/chromium.src,jaruba/chromium.src,M4sse/chromium.src,markYoungH/chromium.src,Jonekee/chromium.src,dednal/chromium.src,dednal/chromium.src,markYoungH/chromium.src,krieger-od/nwjs_chromium.src,jaruba/chromium.src,Jonekee/chromium.src,jaruba/chromium.src,mohamed--abdel-maksoud/chromium.src,jaruba/chromium.src,krieger-od/nwjs_chromium.src,krieger-od/nwjs_chromium.src,dednal/chromium.src,krieger-od/nwjs_chromium.src,jaruba/chromium.src,Jonekee/chromium.src,krieger-od/nwjs_chromium.src,markYoungH/chromium.src,Jonekee/chromium.src,M4sse/chromium.src,dushu1203/chromium.src,Jonekee/chromium.src,dushu1203/chromium.src,dednal/chromium.src,Jonekee/chromium.src,markYoungH/chromium.src,dushu1203/chromium.src,dednal/chromium.src,krieger-od/nwjs_chromium.src,dushu1203/chromium.src,dushu1203/chromium.src,jaruba/chromium.src,M4sse/chromium.src,dednal/chromium.src,M4sse/chromium.src,Jonekee/chromium.src,mohamed--abdel-maksoud/chromium.src,krieger-od/nwjs_chromium.src