layout-tests: Add flag for including compositingReasons in layerTreeAsText().

Source/platform/graphics/GraphicsLayer.cpp

 /*
  * Copyright (C) 2009 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 683 matching lines @@
         json->setArray("paintingPhases", paintingPhasesJSON);
     }
 
     if (flags & LayerTreeIncludesClipAndScrollParents) {
         if (m_hasScrollParent)
             json->setBoolean("hasScrollParent", true);
         if (m_hasClipParent)
             json->setBoolean("hasClipParent", true);
     }
 
-    if (flags & LayerTreeIncludesDebugInfo) {
-        RefPtr<JSONArray> compositingReasonsJSON = adoptRef(new JSONArray);
-        for (size_t i = 0; i < kNumberOfCompositingReasons; ++i) {
-            if (m_debugInfo.compositingReasons() & kCompositingReasonStringMap[i].reason)
-                compositingReasonsJSON->pushString(kCompositingReasonStringMap[i].description);
-        }
-        json->setArray("compositingReasons", compositingReasonsJSON);
+    bool debug = flags & LayerTreeIncludesDebugInfo;
+    RefPtr<JSONArray> compositingReasonsJSON = adoptRef(new JSONArray);
+    for (size_t i = 0; i < kNumberOfCompositingReasons; ++i) {
+        if (m_debugInfo.compositingReasons() & kCompositingReasonStringMap[i].reason)
+            compositingReasonsJSON->pushString(debug ? kCompositingReasonStringMap[i].description : kCompositingReasonStringMap[i].shortName);
     }
+    json->setArray("compositingReasons", compositingReasonsJSON);
 
     if (m_children.size()) {
         RefPtr<JSONArray> childrenJSON = adoptRef(new JSONArray);
         for (size_t i = 0; i < m_children.size(); i++)
             childrenJSON->pushObject(m_children[i]->layerTreeAsJSON(flags, renderingContextMap));
         json->setArray("children", childrenJSON);
     }
 
     return json;
 }
@@ skipping 450 matching lines @@
 {
     if (!layer) {
         fprintf(stderr, "Cannot showGraphicsLayerTree for (nil).\n");
         return;
     }
 
     String output = layer->layerTreeAsText(blink::LayerTreeIncludesDebugInfo);
     fprintf(stderr, "%s\n", output.utf8().data());
 }
 #endif