add SkGraphics::PurageAllCaches

src/core/SkGraphics.cpp

Index: src/core/SkGraphics.cpp
diff --git a/src/core/SkGraphics.cpp b/src/core/SkGraphics.cpp
index 5290ea1d07a9065dc27329947c2a9b32b7e31beb..2b1212c0dceb708b1b3a3f684e37746113ffc6e5 100644
--- a/src/core/SkGraphics.cpp
+++ b/src/core/SkGraphics.cpp
@@ -13,6 +13,7 @@
 #include "SkCanvas.h"
 #include "SkGeometry.h"
 #include "SkGlyphCache.h"
+#include "SkImageFilter.h"
 #include "SkMath.h"
 #include "SkMatrix.h"
 #include "SkOpts.h"
@@ -65,6 +66,12 @@ void SkGraphics::DumpMemoryStatistics(SkTraceMemoryDump* dump) {
   SkGlyphCache::DumpMemoryStatistics(dump);
 }
 
+void SkGraphics::PurgeAllCaches() {
+    SkGraphics::PurgeFontCache();
+    SkGraphics::PurgeResourceCache();
+    SkImageFilter::PurgeCache();
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 static const char kFontCacheLimitStr[] = "font-cache-limit";