Use string for Histogram names since these are all ASCII anyway wide-characte...

net/disk_cache/eviction.cc

Index: net/disk_cache/eviction.cc
===================================================================
--- net/disk_cache/eviction.cc	(revision 10269)
+++ net/disk_cache/eviction.cc	(working copy)
@@ -80,7 +80,7 @@
     }
   }
 
-  UMA_HISTOGRAM_TIMES(L"DiskCache.TotalTrimTime", Time::Now() - start);
+  UMA_HISTOGRAM_TIMES("DiskCache.TotalTrimTime", Time::Now() - start);
   Trace("*** Trim Cache end ***");
   return;
 }
@@ -107,8 +107,8 @@
   static bool first_time = true;
   if (first_time) {
     first_time = false;
-    std::wstring name(StringPrintf(L"DiskCache.TrimAge_%d",
-                                   header_->experiment));
+    std::string name(StringPrintf("DiskCache.TrimAge_%d",
+                                  header_->experiment));
     static Histogram counter(name.c_str(), 1, 10000, 50);
     counter.SetFlags(kUmaTargetedHistogramFlag);
     counter.Add((Time::Now() - entry->GetLastUsed()).InHours());