Speed up GrResourceCache add and lookup by using TDynamicHash

src/core/SkScaledImageCache.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkScaledImageCache.h"
 #include "SkMipMap.h"
 #include "SkOnce.h"
@@ skipping 353 matching lines @@
         if (bytesUsed < byteLimit) {
             break;
         }
         Rec* prev = rec->fPrev;
         if (0 == rec->fLockCount) {
             size_t used = rec->bytesUsed();
             SkASSERT(used <= bytesUsed);
             bytesUsed -= used;
             this->detach(rec);
 #ifdef USE_HASH
-            fHash->remove(rec->fKey);
+            fHash->remove(rec);
 #endif
 
             SkDELETE(rec);
             fCount -= 1;
         }
         rec = prev;
     }
     fBytesUsed = bytesUsed;
 }
 
@@ skipping 204 matching lines @@
     return SkScaledImageCache::GetBytesUsed();
 }
 
 size_t SkGraphics::GetImageCacheByteLimit() {
     return SkScaledImageCache::GetByteLimit();
 }
 
 size_t SkGraphics::SetImageCacheByteLimit(size_t newLimit) {
     return SkScaledImageCache::SetByteLimit(newLimit);
 }