Change undefined SkGpuRenderTarget and SkGpuTexture forward declares to GrRenderTarget and GrTexture.

R=robertphillips@google.com, reed@google.com

Author: bsalomon@google.com

Review URL: https://chromiumcodereview.appspot.com/17269003

git-svn-id: http://skia.googlecode.com/svn/trunk@9775 2bbb7eff-a529-9590-31e7-b0007b416f81
18 files changed