cc: Do solid color analysis before scheduling tiles.

Instead of creating separate analysis task in raster thread for
solid color detection, we do it while scheduling and rasterization
in cc thread itself. This would save us the thread overhead etc.

BUG=553612
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1531013004

Cr-Commit-Position: refs/heads/master@{#369263}
9 files changed