added SkDebugCanvas::toJSON

tools/debugger/SkDebugCanvas.h

Index: tools/debugger/SkDebugCanvas.h
diff --git a/tools/debugger/SkDebugCanvas.h b/tools/debugger/SkDebugCanvas.h
index 217b52e3ce9e77d8b30c6e257bc9dba7ec0e0008..505b5c79fac684447feb36cb6b678df19911c0bd 100644
--- a/tools/debugger/SkDebugCanvas.h
+++ b/tools/debugger/SkDebugCanvas.h
@@ -17,6 +17,7 @@
 #include "SkPicture.h"
 #include "SkString.h"
 #include "SkTArray.h"
+#include "UrlDataManager.h"
 
 class SkNWayCanvas;
 
@@ -139,6 +140,12 @@ public:
 
     SkString clipStackData() const { return fClipStackData; }
 
+    /**
+        Returns a JSON object representing all of the draws. The encoder may use the UrlDataManager
+        to store binary data such as images, referring to them via URLs embedded in the JSON.
+     */
+    Json::Value toJSON(UrlDataManager& urlDataManager);
+
 ////////////////////////////////////////////////////////////////////////////////
 // Inherited from SkCanvas
 ////////////////////////////////////////////////////////////////////////////////