DevTools: return error when trying to load an empty (0 x 0) picture

Source/platform/graphics/PictureSnapshot.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 78 matching lines @@
     SkCanvas* canvas = recorder.beginRecording(unionRect.width(), unionRect.height(), 0, 0);
     for (size_t i = 0; i < pictures.size(); ++i) {
         canvas->save();
         canvas->translate(tiles[i]->layerOffset.x() - unionRect.x(), tiles[i]->layerOffset.y() - unionRect.y());
         pictures[i]->playback(canvas, 0);
         canvas->restore();
     }
     return adoptRef(new PictureSnapshot(adoptRef(recorder.endRecordingAsPicture())));
 }
 
+bool PictureSnapshot::isEmpty() const
+{
+    return m_picture->cullRect().isEmpty();
+}
+
 PassOwnPtr<Vector<char>> PictureSnapshot::replay(unsigned fromStep, unsigned toStep, double scale) const
 {
     const SkIRect bounds = m_picture->cullRect().roundOut();
     SkBitmap bitmap;
     bitmap.allocPixels(SkImageInfo::MakeN32Premul(bounds.width(), bounds.height()));
     bitmap.eraseARGB(0, 0, 0, 0);
     {
         ReplayingCanvas canvas(bitmap, fromStep, toStep);
         canvas.scale(scale, scale);
         canvas.resetStepCount();
@@ skipping 17 matching lines @@
     bitmap.eraseARGB(0, 0, 0, 0);
 
     double now = WTF::monotonicallyIncreasingTime();
     double stopTime = now + minDuration;
     for (unsigned step = 0; step < minRepeatCount || now < stopTime; ++step) {
         timings->append(Vector<double>());
         Vector<double>* currentTimings = &timings->last();
         if (timings->size() > 1)
             currentTimings->reserveCapacity(timings->begin()->size());
         ProfilingCanvas canvas(bitmap);
-        if (clipRect)
+        if (clipRect) {
             canvas.clipRect(SkRect::MakeXYWH(clipRect->x(), clipRect->y(), clipRect->width(), clipRect->height()));
+            canvas.resetStepCount();
+        }
         canvas.setTimings(currentTimings);
         m_picture->playback(&canvas);
         now = WTF::monotonicallyIncreasingTime();
     }
     return timings.release();
 }
 
 PassRefPtr<JSONArray> PictureSnapshot::snapshotCommandLog() const
 {
     const SkIRect bounds = m_picture->cullRect().roundOut();
     LoggingCanvas canvas(bounds.width(), bounds.height());
     m_picture->playback(&canvas);
     return canvas.log();
 }
 
 } // namespace blink