Image filters: Replace all use of tryAllocPixels() with createDevice().

Image filters: Replace all use of tryAllocPixels() with createDevice().

In order to have a central pinch point for bitmap allocation, change all
filters to use Proxy::createDevice() instead of allocating memory
directly with SkBitmap::tryAllocPixels().

This will aid in moving filter backing stores and caches to
discardable memory.

BUG=skia:

Review URL: https://codereview.chromium.org/1414843003