Allow the default browser check to return "unknown" and reflect that in the UI.

chrome/browser/shell_integration_mac.mm

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/shell_integration.h"
 
 #include "base/mac_util.h"
 #import "third_party/mozilla/include/NSWorkspace+Utils.h"
 
 // Sets Chromium as default browser (only for current user). Returns false if
 // this operation fails (which we can't check for).
 bool ShellIntegration::SetAsDefaultBrowser() {
   NSBundle* mainBundle = mac_util::MainAppBundle();
   NSString* identifier = [mainBundle bundleIdentifier];
   [[NSWorkspace sharedWorkspace] setDefaultBrowserWithIdentifier:identifier];
   return true;
 }
 
 namespace {
 
 // Returns true if |identifier| is the bundle id of the default browser.
 bool IsIdentifierDefaultBrowser(NSString* identifier) {
   NSString* defaultBrowser =
       [[NSWorkspace sharedWorkspace] defaultBrowserIdentifier];
-  if (!identifier || !defaultBrowser)
+  if (!defaultBrowser)
     return false;
   // We need to ensure we do the comparison case-insensitive as LS doesn't
   // persist the case of our bundle id.
   NSComparisonResult result =
     [defaultBrowser caseInsensitiveCompare:identifier];
   return result == NSOrderedSame;
 }
 
 }  // namespace
 
-// Returns true if this instance of Chromium is the default browser. (Defined
-// as being the handler for the http/https protocols... we don't want to
-// report false here if the user has simply chosen to open HTML files in a
-// text editor and ftp links with a FTP client).
-bool ShellIntegration::IsDefaultBrowser() {
+// Attempt to determine if this instance of Chrome is the default browser and
+// return the appropriate state. (Defined as being the handler for HTTP/HTTPS
+// protocols; we don't want to report "no" here if the user has simply chosen
+// to open HTML files in a text editor and FTP links with an FTP client.)
+ShellIntegration::DefaultBrowserState ShellIntegration::IsDefaultBrowser() {
   NSBundle* mainBundle = mac_util::MainAppBundle();
   NSString* myIdentifier = [mainBundle bundleIdentifier];

[Evan Martin, 2009/09/04 22:46:15]

Why can this return null now after your change?

[Mike Mammarella, 2009/09/04 22:56:27]

Presumably it could have before as well; I just moved the check from
IsIdentifierDefaultBrowser() to here because it now results in a different
return value ("unknown" vs. "no").

-  return IsIdentifierDefaultBrowser(myIdentifier);
+  if (!myIdentifier)
+    return UNKNOWN_DEFAULT_BROWSER;
+  return IsIdentifierDefaultBrowser(myIdentifier) ? IS_DEFAULT_BROWSER
+                                                  : NOT_DEFAULT_BROWSER;
 }
 
 // Returns true if Firefox is the default browser for the current user.
 bool ShellIntegration::IsFirefoxDefaultBrowser() {
   return IsIdentifierDefaultBrowser(@"org.mozilla.firefox");
 }