hack

src/core/SkCanvas.cpp

Index: src/core/SkCanvas.cpp
===================================================================
--- src/core/SkCanvas.cpp	(revision 14079)
+++ src/core/SkCanvas.cpp	(working copy)
@@ -2547,7 +2547,7 @@
     if (NULL != device) {
         // Canvas has to first give the device the opportunity to render
         // the picture itself.
-        if (device->EXPERIMENTAL_drawPicture(&picture)) {
+        if (device->EXPERIMENTAL_drawPicture(this, &picture)) {
             return; // the device has rendered the entire picture
         }
     }
@@ -2555,6 +2555,13 @@
     picture.draw(this);
 }
 
+void SkCanvas::EXPERIMENTAL_purge() {
+    SkBaseDevice* device = this->getTopDevice();
+    if (NULL != device) {
+        device->EXPERIMENTAL_purge();
+    }
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 ///////////////////////////////////////////////////////////////////////////////