Image filters: de-nest SkImageFilter::Cache and Cache::Key.

src/core/SkBitmapDevice.cpp

Index: src/core/SkBitmapDevice.cpp
diff --git a/src/core/SkBitmapDevice.cpp b/src/core/SkBitmapDevice.cpp
index 8a517a6f00ca870448f4d41f99d76eb21e4a2482..119a434cc9cde8a5077a18702ba2394e67a183f8 100644
--- a/src/core/SkBitmapDevice.cpp
+++ b/src/core/SkBitmapDevice.cpp
@@ -8,6 +8,7 @@
 #include "SkBitmapDevice.h"
 #include "SkConfig8888.h"
 #include "SkDraw.h"
+#include "SkImageFilterCache.h"
 #include "SkMallocPixelRef.h"
 #include "SkMatrix.h"
 #include "SkPaint.h"
@@ -367,8 +368,8 @@ sk_sp<SkSurface> SkBitmapDevice::makeSurface(const SkImageInfo& info, const SkSu
     return SkSurface::MakeRaster(info, &props);
 }
 
-SkImageFilter::Cache* SkBitmapDevice::getImageFilterCache() {
-    SkImageFilter::Cache* cache = SkImageFilter::Cache::Get();
+SkImageFilterCache* SkBitmapDevice::getImageFilterCache() {
+    SkImageFilterCache* cache = SkImageFilterCache::Get();
     cache->ref();
     return cache;
 }