Replace scaled bitmap if entry already exist in cache.

src/core/SkScaledImageCache.cpp

Index: src/core/SkScaledImageCache.cpp
diff --git a/src/core/SkScaledImageCache.cpp b/src/core/SkScaledImageCache.cpp
index f0f34ccbf17533d5f019907343b7d13fb124d03c..c436417f281b7463737c27bb31be758c8423ff7c 100644
--- a/src/core/SkScaledImageCache.cpp
+++ b/src/core/SkScaledImageCache.cpp
@@ -425,6 +425,7 @@ SkScaledImageCache::ID* SkScaledImageCache::addAndLock(SkScaledImageCache::Rec*
     if (NULL != existing) {
         // Since we already have a matching entry, just delete the new one and return.
         // Call sites cannot assume the passed in object will live past this call.
+        existing->fBitmap = rec->fBitmap;
         SkDELETE(rec);
         return rec_to_id(existing);
     }