Have the Debugger extension api check that it has access to the tab

extensions/common/url_pattern.h

Index: extensions/common/url_pattern.h
diff --git a/extensions/common/url_pattern.h b/extensions/common/url_pattern.h
index 70109dbf03027864f7b99f1e62aa435ab2c8d499..b4c566bf5c316a46ea060425c9cb476574e1c8e5 100644
--- a/extensions/common/url_pattern.h
+++ b/extensions/common/url_pattern.h
@@ -78,6 +78,9 @@ class URLPattern {
   // The <all_urls> string pattern.
   static const char kAllUrlsPattern[];
 
+  // Returns true if the given |scheme| is considered valid for extensions.
+  static bool IsValidSchemeForExtensions(const std::string& scheme);
+
   explicit URLPattern(int valid_schemes);
 
   // Convenience to construct a URLPattern from a string. If the string is not