Cherry-pick: aw: Disable hardware features for software layer

Cherry-pick of crrev.com/r257037.

Conflicts:
	android_webview/java/src/org/chromium/android_webview/AwContents.java

Original description:

If the webview is put into a software layer, then disable hardware only
features such as accelerated canvas even if we are attached to a
hardware view tree.

Previously we did not take layer type into account.

BUG: 13328348
Change-Id: I1e43056d52074ea79c18f1a56cfe3a9e7e1835d0
1 file changed