Cherry-pick: [Android WebView] Turn on accelerated canvas based on View.isHardwareAccelerated

Clean cherry-pick of

Original description:

In onAttachedToWindow, check that if the view is hardware accelerated,
then enable hardware accelerated 2d canvas. Similarly disable canvas on

Note that accelerated 2d canvas is still off by default, but this patch
adds a command line switch to turn it on.

BUG: 13328348

Change-Id: I7ceb7b4ef6cefca6b37f7911357fbcd9e2dbef6b
7 files changed