Pass format as argument to getContentBitmapAsync.
getScaledContentbitmap can process and give output
in the requested format. getContentBitmapAsync should have
this support. Especially on low-end devices we may need
bitmaps with 16-bit formats.

BUG=472457

Review URL: https://codereview.chromium.org/1021863005

Cr-Commit-Position: refs/heads/master@{#323194}
3 files changed