cc: Remove texture scaling and clear edge texels of a layer.

cc: Remove texture scaling and clear edge texels of a layer.

Removes texture scaling and does the following instead:

- Clears one texel inside the right/bottom edge of the content rect,
  as it may only be partially covered by the picture playback.
- Also clears one texel outside the right/bottom edge of the content
  rect, as it may get blended in by linear filtering when zoomed in.

The root layer is cleared to its background color.
Other layers are cleared to transparent.

BUG=178273
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=185732

[enne (OOO), 2013-03-01 20:58:04]

lgtm!

[enne (OOO), 2013-03-01 22:49:34]

Still lgtm.

[commit-bot: I haz the power, 2013-03-01 23:04:25]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/brianderson@chromium.org/12383060/12002

[commit-bot: I haz the power, 2013-03-02 16:25:03]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/brianderson@chromium.org/12383060/12002

[commit-bot: I haz the power, 2013-03-02 18:00:42]

Change committed as 185732