Remove incorrect GrAssert calls in GrResourceCache::removeAll

The asserts in GrResourceCache are too aggressive, and assume that all resources are always purged.  Locked resources will not be purged.

BUG=114861
Review URL: https://codereview.appspot.com/5674096

git-svn-id: http://skia.googlecode.com/svn/trunk@3226 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed