Wire up stack traces again

src/gpu/GrAuditTrail.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrAuditTrail.h"
 #include "batches/GrBatch.h"
 
 const int GrAuditTrail::kGrAuditTrailInvalidID = -1;
 
 void GrAuditTrail::addBatch(const char* name, const SkRect& bounds) {
     SkASSERT(fEnabled);
     Batch* batch = new Batch;
     fBatchPool.emplace_back(batch);
     batch->fName = name;
     batch->fBounds = bounds;
     batch->fClientID = kGrAuditTrailInvalidID;
     batch->fBatchListID = kGrAuditTrailInvalidID;
     batch->fChildID = kGrAuditTrailInvalidID;
+    
+    // consume the current stack trace if any
+    batch->fStackTrace = fCurrentStackTrace;
+    fCurrentStackTrace.reset();
     fCurrentBatch = batch;
     
     if (fClientID != kGrAuditTrailInvalidID) {
         batch->fClientID = fClientID;
         Batches** batchesLookup = fClientIDLookup.find(fClientID);
         Batches* batches = nullptr;
         if (!batchesLookup) {
             batches = new Batches;
             fClientIDLookup.set(fClientID, batches);
         } else {
@@ skipping 203 matching lines @@
 }
 
 SkString GrAuditTrail::Batch::toJson() const {
     SkString json;
     json.append("{");
     json.appendf("\"Name\": \"%s\",", fName.c_str());
     json.appendf("\"ClientID\": \"%d\",", fClientID);
     json.appendf("\"BatchListID\": \"%d\",", fBatchListID);
     json.appendf("\"ChildID\": \"%d\",", fChildID);
     skrect_to_json(&json, "Bounds", fBounds);
+    if (fStackTrace.count()) {
+        json.append(",\"Stack\": [");
+        for (int i = 0; i < fStackTrace.count(); i++) {
+            json.appendf("\"%s\"", fStackTrace[i].c_str());
+            if (i < fStackTrace.count() - 1) {
+                json.append(",");
+            }
+        }
+        json.append("]");
+    }
     json.append("}");
     return json;
 }
 
 SkString GrAuditTrail::BatchNode::toJson() const {
     SkString json;
     json.append("{");
     json.appendf("\"RenderTarget\": \"%u\",", fRenderTargetUniqueID);
     skrect_to_json(&json, "Bounds", fBounds);
     JsonifyTArray(&json, "Batches", fChildren, true);
     json.append("}");
     return json;
 }