purge imagefilter cache so we can better track leaks

src/core/SkResourceCache.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkChecksum.h"
 #include "SkMessageBus.h"
 #include "SkMipMap.h"
@@ skipping 600 matching lines @@
 
 void SkResourceCache::PostPurgeSharedID(uint64_t sharedID) {
     if (sharedID) {
         SkMessageBus<PurgeSharedIDMessage>::Post(PurgeSharedIDMessage(sharedID));
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 #include "SkGraphics.h"
+#include "SkImageFilter.h"
 
 size_t SkGraphics::GetResourceCacheTotalBytesUsed() {
     return SkResourceCache::GetTotalBytesUsed();
 }
 
 size_t SkGraphics::GetResourceCacheTotalByteLimit() {
     return SkResourceCache::GetTotalByteLimit();
 }
 
 size_t SkGraphics::SetResourceCacheTotalByteLimit(size_t newLimit) {
     return SkResourceCache::SetTotalByteLimit(newLimit);
 }
 
 size_t SkGraphics::GetResourceCacheSingleAllocationByteLimit() {
     return SkResourceCache::GetSingleAllocationByteLimit();
 }
 
 size_t SkGraphics::SetResourceCacheSingleAllocationByteLimit(size_t newLimit) {
     return SkResourceCache::SetSingleAllocationByteLimit(newLimit);
 }
 
 void SkGraphics::PurgeResourceCache() {
+    SkImageFilter::PurgeCache();
     return SkResourceCache::PurgeAll();
 }