Remove unused header file in SkScaledImageCache.cpp

BUG=skia:
R=reed@google.com

Author: qiankun.miao@intel.com

Review URL: https://codereview.chromium.org/506783003
diff --git a/src/core/SkScaledImageCache.cpp b/src/core/SkScaledImageCache.cpp
index 9e672fe..6a24b5d 100644
--- a/src/core/SkScaledImageCache.cpp
+++ b/src/core/SkScaledImageCache.cpp
@@ -9,7 +9,6 @@
 #include "SkScaledImageCache.h"
 #include "SkMipMap.h"
 #include "SkPixelRef.h"
-#include "SkRect.h"
 
 // This can be defined by the caller's build system
 //#define SK_USE_DISCARDABLE_SCALEDIMAGECACHE