Re-implement app overlap detection with new extent syntax.

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 62d3d8fbe5cd565fb8b04ec3a482f34afe9526e1..fd1cefe277800654563b8745a611c8419c86f05c 100644
--- a/chrome/common/extensions/url_pattern.h
+++ b/chrome/common/extensions/url_pattern.h
@@ -78,15 +78,6 @@ class URLPattern {
 
   URLPattern() : match_subdomains_(false) {}
 
-  // Initializes this instance by parsing the provided string. On failure, the
-  // instance will have some intermediate values and is in an invalid state.
-  bool Parse(const std::string& pattern_str);
-
-  // Returns true if this instance matches the specified URL.
-  bool MatchesUrl(const GURL& url) const;
-
-  std::string GetAsString() const;
-
   // Get the scheme the pattern matches. This will always return a valid scheme
   // if is_valid() returns true.
   std::string scheme() const { return scheme_; }
@@ -109,12 +100,28 @@ class URLPattern {
     path_escaped_ = "";
   }
 
+  // Initializes this instance by parsing the provided string. On failure, the
+  // instance will have some intermediate values and is in an invalid state.
+  bool Parse(const std::string& pattern_str);
+
+  // Returns true if this instance matches the specified URL.
+  bool MatchesUrl(const GURL& url) const;
+
+  // Returns a string representing this instance.
+  std::string GetAsString() const;
+
+  // Determine whether there is a URL that would match this instance and another
+  // instance. This method is symmetrical: Calling other.OverlapsWith(this)
+  // would result in the same answer.
+  bool OverlapsWith(const URLPattern& other) const;
+
  private:
   // Returns true if |test| matches our host.
+  bool MatchesHost(const std::string& host) const;
   bool MatchesHost(const GURL& test) const;
 
   // Returns true if |test| matches our path.
-  bool MatchesPath(const GURL& test) const;
+  bool MatchesPath(const std::string& test) const;
 
   // The scheme for the pattern.
   std::string scheme_;