Revert of GrResourceCache2 manages scratch texture. (patchset #14 id:260001 of https://codereview.chromium.org/608883003/)

Reason for revert:
Turning bots red:
Nanobench seems to be uniformly failing on Android
(http://108.170.220.21:10117/builders/Perf-Android-Venue8-PowerVR-x86-Release/builds/99/steps/RunNanobench/logs/stdio)

Ubuntu GTX660 32bit is failing in both Debug and Release on GM generation (it appears to be out of memory) (http://108.170.220.120:10117/builders/Test-Ubuntu12-ShuttleA-GTX660-x86-Debug/builds/2457/steps/GenerateGMs/logs/stdio)

Original issue's description:
> GrResourceCache2 manages scratch texture.
>
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/3d398c876440deaab39bbf2a9b881c337e6dc8d4

R=bsalomon@google.com
TBR=bsalomon@google.com
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Author: robertphillips@google.com

Review URL: https://codereview.chromium.org/611383003
diff --git a/src/gpu/SkGpuDevice.h b/src/gpu/SkGpuDevice.h
index fe03e32..285a737 100644
--- a/src/gpu/SkGpuDevice.h
+++ b/src/gpu/SkGpuDevice.h
@@ -34,7 +34,8 @@
 public:
     enum Flags {
         kNeedClear_Flag = 1 << 0,  //!< Surface requires an initial clear
-        kDFFonts_Flag   = 1 << 1,  //!< Surface should render fonts using signed distance fields
+        kCached_Flag    = 1 << 1,  //!< Surface is cached and needs to be unlocked when released
+        kDFFonts_Flag   = 1 << 2,  //!< Surface should render fonts using signed distance fields
     };
 
     /**
@@ -116,6 +117,9 @@
                              const SkImageFilter::Context&,
                              SkBitmap*, SkIPoint*) SK_OVERRIDE;
 
+    class SkAutoCachedTexture; // used internally
+
+
 protected:
     virtual bool onReadPixels(const SkImageInfo&, void*, size_t, int, int) SK_OVERRIDE;
     virtual bool onWritePixels(const SkImageInfo&, const void*, size_t, int, int) SK_OVERRIDE;