Use base::StartWith() in more places when appropriate.

chrome/renderer/pepper/pepper_uma_host.cc

Index: chrome/renderer/pepper/pepper_uma_host.cc
diff --git a/chrome/renderer/pepper/pepper_uma_host.cc b/chrome/renderer/pepper/pepper_uma_host.cc
index 6a1e5a32dbbf8c6dfa57877b2ff99066a483ceab..56ef732c6648c20bb7363e113b3b2c360281cea8 100644
--- a/chrome/renderer/pepper/pepper_uma_host.cc
+++ b/chrome/renderer/pepper/pepper_uma_host.cc
@@ -10,6 +10,7 @@
 #include "base/metrics/histogram.h"
 #include "base/sha1.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
 #include "chrome/common/chrome_content_client.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/render_messages.h"
@@ -113,7 +114,8 @@ bool PepperUMAHost::IsPluginWhitelisted() {
 }
 
 bool PepperUMAHost::IsHistogramAllowed(const std::string& histogram) {
-  if (is_plugin_in_process_ && histogram.find("NaCl.") == 0) {
+  if (is_plugin_in_process_ &&
+      base::StartsWith(histogram, "NaCl.", base::CompareCase::SENSITIVE)) {
     return true;
   }