Revert of GrResourceCache2 manages scratch texture.

include/gpu/GrContext.h

Index: include/gpu/GrContext.h
diff --git a/include/gpu/GrContext.h b/include/gpu/GrContext.h
index d2f3729f15190a93c708ee0055636dbc303d05c9..e1af73ccb2497c9cbea64b248aa5b9b6bf5c1c2f 100644
--- a/include/gpu/GrContext.h
+++ b/include/gpu/GrContext.h
@@ -295,6 +295,12 @@
     GrTexture* lockAndRefScratchTexture(const GrTextureDesc&, ScratchTexMatch match);
 
     /**
+     *  When done with an entry, call unlockScratchTexture(entry) on it, which returns
+     *  it to the cache, where it may be purged. This does not unref the texture.
+     */
+    void unlockScratchTexture(GrTexture* texture);
+
+    /**
      * Creates a texture that is outside the cache. Does not count against
      * cache's budget.
      */
@@ -1045,7 +1051,15 @@
                                     size_t rowBytes,
                                     bool filter);
 
-    bool createNewScratchTexture(const GrTextureDesc& desc);
+    // Needed so GrTexture's returnToCache helper function can call
+    // addExistingTextureToCache
+    friend class GrTexture;
+    friend class GrStencilAndCoverPathRenderer;
+    friend class GrStencilAndCoverTextContext;
+
+    // Add an existing texture to the texture cache. This is intended solely
+    // for use with textures released from an GrAutoScratchTexture.
+    void addExistingTextureToCache(GrTexture* texture);
 
     /**
      * These functions create premul <-> unpremul effects if it is possible to generate a pair
@@ -1065,7 +1079,8 @@
 };
 
 /**
- * This is deprecated. Don't use it.
+ * Gets and locks a scratch texture from a descriptor using either exact or approximate criteria.
+ * Unlocks texture in the destructor.
  */
 class GrAutoScratchTexture : public ::SkNoncopyable {
 public:
@@ -1088,16 +1103,25 @@
 
     void reset() {
         if (fContext && fTexture) {
+            fContext->unlockScratchTexture(fTexture);
             fTexture->unref();
             fTexture = NULL;
         }
     }
 
-    GrTexture* detach() {
-        GrTexture* texture = fTexture;
-        fTexture = NULL;
-        return texture;
-    }
+    /*
+     * When detaching a texture we do not unlock it in the texture cache but
+     * we do set the returnToCache flag. In this way the texture remains
+     * "locked" in the texture cache until it is freed and recycled in
+     * GrTexture::internal_dispose. In reality, the texture has been removed
+     * from the cache (because this is in AutoScratchTexture) and by not
+     * calling unlockScratchTexture we simply don't re-add it. It will be
+     * reattached in GrTexture::internal_dispose.
+     *
+     * Note that the caller is assumed to accept and manage the ref to the
+     * returned texture.
+     */
+    GrTexture* detach();
 
     GrTexture* set(GrContext* context,
                    const GrTextureDesc& desc,