Fix the compile error for win64: widevine_key_systems.cc.

components/cdm/renderer/widevine_key_systems.cc

Index: components/cdm/renderer/widevine_key_systems.cc
diff --git a/components/cdm/renderer/widevine_key_systems.cc b/components/cdm/renderer/widevine_key_systems.cc
index d42ec7d680c7cd268e6a37cfd0655a85f1cc176c..0b37a7143c416d296b89d8e04cce5c8efc874142 100644
--- a/components/cdm/renderer/widevine_key_systems.cc
+++ b/components/cdm/renderer/widevine_key_systems.cc
@@ -23,7 +23,7 @@ namespace cdm {
 
 // Return |name|'s parent key system.
 static std::string GetDirectParentName(std::string name) {
-  int last_period = name.find_last_of('.');
+  size_t last_period = name.find_last_of('.');
   DCHECK_GT(last_period, 0);

[xhwang, 2014/05/09 23:59:22]

s/0/0u?

[ycheo (away), 2014/05/10 00:03:45]

Hmm. actually, size_t is unsigned.
Isn't it better to remove this?

   return name.substr(0, last_period);
 }