Use lock-free lazy initialization for static histogram references

webkit/glue/webkitclient_impl.cc

Index: webkit/glue/webkitclient_impl.cc
===================================================================
--- webkit/glue/webkitclient_impl.cc	(revision 79771)
+++ webkit/glue/webkitclient_impl.cc	(working copy)
@@ -264,24 +264,22 @@
     const char* name, int sample, int min, int max, int bucket_count) {
   // Copied from histogram macro, but without the static variable caching
   // the histogram because name is dynamic.
-  scoped_refptr<base::Histogram> counter =
+  base::Histogram* counter =
       base::Histogram::FactoryGet(name, min, max, bucket_count,
           base::Histogram::kUmaTargetedHistogramFlag);
   DCHECK_EQ(name, counter->histogram_name());
-  if (counter.get())
-    counter->Add(sample);
+  counter->Add(sample);
 }
 
 void WebKitClientImpl::histogramEnumeration(
     const char* name, int sample, int boundary_value) {
   // Copied from histogram macro, but without the static variable caching
   // the histogram because name is dynamic.
-  scoped_refptr<base::Histogram> counter =
+  base::Histogram* counter =
       base::LinearHistogram::FactoryGet(name, 1, boundary_value,
           boundary_value + 1, base::Histogram::kUmaTargetedHistogramFlag);
   DCHECK_EQ(name, counter->histogram_name());
-  if (counter.get())
-    counter->Add(sample);
+  counter->Add(sample);
 }
 
 void WebKitClientImpl::traceEventBegin(const char* name, void* id,