Fix a memory leak in ExtensionExtentUnittest by fixing a bad

chrome/common/extensions/url_pattern.h

Index: chrome/common/extensions/url_pattern.h
diff --git a/chrome/common/extensions/url_pattern.h b/chrome/common/extensions/url_pattern.h
index e25faafe210c9f5f1deda8b9c45793f361f7733b..30f2c0f885ad3347b9d08bef859afc18c9a2f026 100644
--- a/chrome/common/extensions/url_pattern.h
+++ b/chrome/common/extensions/url_pattern.h
@@ -73,10 +73,12 @@ class URLPattern {
   // otherwise.
   static bool IsValidScheme(const std::string& scheme);
 
-  // Convenience to create a pattern from a string.
-  static URLPattern* CreateFromString(const std::string& pattern);
+  URLPattern();
 
-  URLPattern() : match_subdomains_(false) {}
+  // Convenience to construct a URLPattern from a string. The string is expected
+  // to be a valid pattern. If the string is not known ahead of time, use
+  // Parse() instead, which returns success or failure.
+  explicit URLPattern(const std::string& pattern);
 
   // Initializes this instance by parsing the provided string. On failure, the
   // instance will have some intermediate values and is in an invalid state.