Use size of SkRect as the key for blur mask cache

src/core/SkMaskCache.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkMaskCache.h"
 
 #define CHECK_LOCAL(localCache, localName, globalName, ...) \
@@ skipping 86 matching lines @@
 
 struct RectsBlurKey : public SkResourceCache::Key {
 public:
     RectsBlurKey(SkScalar sigma, SkBlurStyle style, SkBlurQuality quality,
                  const SkRect rects[], int count)
         : fSigma(sigma)
         , fStyle(style)
         , fQuality(quality)
     {
         SkASSERT(1 == count || 2 == count);
-        fRects[0] = SkRect::MakeEmpty();
-        fRects[1] = SkRect::MakeEmpty();
+        SkIRect ir;
+        rects[0].roundOut(&ir);
+        fSizes[0] = SkSize::Make(0, 0);
+        fSizes[1] = SkSize::Make(0, 0);
+        fSizes[2] = SkSize::Make(0, 0);
+        fSizes[3] = SkSize::Make(rects[0].x() - ir.x(), rects[0].y() - ir.y());
         for (int i = 0; i < count; i++) {
-            fRects[i] = rects[i];
+            fSizes[i] = SkSize::Make(rects[i].width(), rects[i].height());
         }
+        if (2 == count) {
+            fSizes[2] = SkSize::Make(rects[0].x() - rects[1].x(), rects[0].y() - rects[1].y());
+        }
+
         this->init(&gRectsBlurKeyNamespaceLabel,
-                   sizeof(fSigma) + sizeof(fStyle) + sizeof(fQuality) + sizeof(fRects));
+                   sizeof(fSigma) + sizeof(fStyle) + sizeof(fQuality) + sizeof(fSizes));
     }
 
     SkScalar    fSigma;
     int32_t     fStyle;
     int32_t     fQuality;
-    SkRect      fRects[2];
+    SkSize      fSizes[4];
 };
 
 struct RectsBlurRec : public SkResourceCache::Rec {
     RectsBlurRec(RectsBlurKey key, const SkMask& mask, SkCachedData* data)
         : fKey(key)
     {
         fValue.fMask = mask;
         fValue.fData = data;
         fValue.fData->attachToCacheAndRef();
     }
@@ skipping 36 matching lines @@
     mask->fImage = (uint8_t*)(result.fData->data());
     return result.fData;
 }
 
 void SkMaskCache::Add(SkScalar sigma, SkBlurStyle style, SkBlurQuality quality,
                       const SkRect rects[], int count, const SkMask& mask, SkCachedData* data,
                       SkResourceCache* localCache) {
     RectsBlurKey key(sigma, style, quality, rects, count);
     return CHECK_LOCAL(localCache, add, Add, SkNEW_ARGS(RectsBlurRec, (key, mask, data)));
 }