GitLab

Removed SkBitmapFactory since no clients were using it.  New cache
selection mechanism can simply pass a SkDiscardableMemory::Factory
into the SkDiscardablePixelRef if non-default SkDiscardableMemory
should be used.  Removed BitmapFactoryTest.

SkDiscardableMemory::Factory interface.  Android will need this
functionality in the future inside their BitmapFactory.

Removed SkLazyPixelRef, since it's functionality is now subsumed into
SkDiscardablePixelRef.  Removed LazyPixelRef test.

Modified SkDiscardablePixelRef to optionally allow it to use a
SkDiscardableMemory::Factory.  This tiny change makes it a replacement
for SkLazyPixelRef.  This functioanlity is also necessary for moving
Android over to SkDiscardablePixelRef from SkImageRef in a later CL.
Added a test for this.

SkDecodingImageGenerator::Install can optionally pass a factory in to
SkDiscardablePixelRef.

Removed SkImageCache, SkLruImageCache, and SkPurgeableImageCache.
This functionalit...