SkDebugCanvas ignore batch bounds if they are offscreen

include/private/GrAuditTrail.h

Index: include/private/GrAuditTrail.h
diff --git a/include/private/GrAuditTrail.h b/include/private/GrAuditTrail.h
index 57e0feab6fc3183076005c225dde32274b38b00e..14873cd78c36712064af54f92e520fbd618314b9 100644
--- a/include/private/GrAuditTrail.h
+++ b/include/private/GrAuditTrail.h
@@ -129,6 +129,7 @@ public:
     // a performance issue, but until then its nice to decouple
     struct BatchInfo {
         SkRect fBounds;
+        uint32_t fRenderTargetUniqueID;
         struct Batch {
             int fClientID;
             SkRect fBounds;
@@ -168,6 +169,7 @@ private:
         SkString toJson() const;
         SkRect fBounds;
         Batches fChildren;
+        uint32_t fRenderTargetUniqueID;
     };
     typedef SkTArray<SkAutoTDelete<BatchNode>, true> BatchList;