Optimize CSS box-shadow performance

src/core/SkBitmapCache.cpp

Index: src/core/SkBitmapCache.cpp
diff --git a/src/core/SkBitmapCache.cpp b/src/core/SkBitmapCache.cpp
index de52b63b5e7eda5209f21d87e99eb8a42b66877a..a5bc8646c4ffbca1d2ebfbac38ac6420ff5b019f 100644
--- a/src/core/SkBitmapCache.cpp
+++ b/src/core/SkBitmapCache.cpp
@@ -39,6 +39,34 @@ public:
     SkIRect     fBounds;
 };
 
+struct RRectBlurKey : public SkScaledImageCache::Key {
+public:
+    RRectBlurKey(SkScalar sigma, const SkRRect rrect)
+        : fSigma(sigma)
+        , fRRect(rrect) {
+        this->init(sizeof(fSigma) + sizeof(fRRect));
+    }
+
+    SkScalar    fSigma;
+    SkRRect     fRRect;
+};
+
+struct RectsBlurKey : public SkScaledImageCache::Key {
+public:
+    RectsBlurKey(SkScalar sigma, int32_t count, const SkRect rects[])
+        : fSigma(sigma)
+        , fRecCount(count) {
+        for (int i = 0; i < count; i++) {
+            fRects[i] = rects[i];
+        }
+        this->init(sizeof(fSigma) + sizeof(fRecCount) + sizeof(SkRect) * fRecCount);
+    }
+
+    SkScalar    fSigma;
+    int32_t     fRecCount;
+    SkRect      fRects[2];
+};
+
 //////////////////////////////////////////////////////////////////////////////////////////
 
 SkScaledImageCache::ID* SkBitmapCache::FindAndLock(const SkBitmap& src,
@@ -89,3 +117,37 @@ SkScaledImageCache::ID* SkMipMapCache::AddAndLock(const SkBitmap& src, const SkM
     return SkScaledImageCache::AddAndLock(key, result);
 }
 
+////
+
+SkScaledImageCache::ID* SkBitmapCache::FindAndLock(SkScalar sigma,
+                                                   const SkRRect rrect,
+                                                   SkBitmap* result) {
+    RRectBlurKey key(sigma, rrect);
+    return SkScaledImageCache::FindAndLock(key, result);
+}
+
+SkScaledImageCache::ID* SkBitmapCache::AddAndLock(SkScalar sigma,
+                                                  const SkRRect rrect,
+                                                  const SkBitmap& bitmap) {
+    RRectBlurKey key(sigma, rrect);
+    return SkScaledImageCache::AddAndLock(key, bitmap);
+}
+
+////
+
+SkScaledImageCache::ID* SkBitmapCache::FindAndLock(SkScalar sigma,
+                                                   unsigned count,
+                                                   const SkRect rects[],
+                                                   SkBitmap* result) {
+    RectsBlurKey key(sigma, count, rects);
+    return SkScaledImageCache::FindAndLock(key, result);
+}
+
+SkScaledImageCache::ID* SkBitmapCache::AddAndLock(SkScalar sigma,
+                                                  unsigned count,
+                                                  const SkRect rects[],
+                                                  const SkBitmap& bitmap) {
+    RectsBlurKey key(sigma, count, rects);
+    return SkScaledImageCache::AddAndLock(key, bitmap);
+}
+