Fix performance issue in InstanceCounters for DOM nodes

third_party/WebKit/Source/core/inspector/InstanceCounters.cpp

Index: third_party/WebKit/Source/core/inspector/InstanceCounters.cpp
diff --git a/third_party/WebKit/Source/core/inspector/InstanceCounters.cpp b/third_party/WebKit/Source/core/inspector/InstanceCounters.cpp
index c5948b98763ac088a1d4ea12c76fa93d1f63709a..0ddab665a698447c34b9babf5d1e583614b6ee56 100644
--- a/third_party/WebKit/Source/core/inspector/InstanceCounters.cpp
+++ b/third_party/WebKit/Source/core/inspector/InstanceCounters.cpp
@@ -34,7 +34,13 @@ namespace blink {
 
 int InstanceCounters::s_counters[CounterTypeLength];
 
+int InstanceCounters::s_nodeCounter;

[haraken, 2016/10/06 08:47:10]

Add a comment and mention why we want to have a different counter for Nodes.

[hajimehoshi, 2016/10/06 09:34:52]

Done.

+
 int InstanceCounters::counterValue(CounterType type) {
+  if (type == NodeCounter) {
+    DCHECK(isMainThread());
+    return s_nodeCounter;
+  }
   return acquireLoad(&s_counters[type]);
 }