Complete XXXPaintPropertyNode::operator== and toString()

third_party/WebKit/Source/platform/graphics/CompositingReasons.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "platform/graphics/CompositingReasons.h"
 
 #include "wtf/StdLibExtras.h"
+#include "wtf/text/StringBuilder.h"
 
 namespace blink {
 
 const CompositingReasonStringMap kCompositingReasonStringMap[] = {
     {CompositingReasonNone, "Unknown", "No reason given"},
     {CompositingReason3DTransform, "transform3D", "Has a 3d transform"},
     {CompositingReasonVideo, "video", "Is an accelerated video"},
     {CompositingReasonCanvas, "canvas",
      "Is an accelerated canvas, or is a display list backed canvas that was "
      "promoted to a layer based on a performance heuristic."},
@@ skipping 116 matching lines @@
     {CompositingReasonLayerForDecoration, "layerForDecoration",
      "Layer painted on top of other layers as decoration"},
     {CompositingReasonInlineTransform, "inlineTransform",
      "Has an inline transform, which causes subsequent layers to assume "
      "overlap"},
 };
 
 const size_t kNumberOfCompositingReasons =
     WTF_ARRAY_LENGTH(kCompositingReasonStringMap);
 
+String compositingReasonsAsString(CompositingReasons reasons) {
+  if (!reasons)
+    return "none";
+
+  StringBuilder builder;
+  for (size_t i = 0; i < kNumberOfCompositingReasons; ++i) {
+    if (reasons & kCompositingReasonStringMap[i].reason) {
+      if (builder.length())
+        builder.append(',');
+      builder.append(kCompositingReasonStringMap[i].shortName);
+    }
+  }
+  return builder.toString();
+}
+
 }  // namespace blink