Improve error message for failing code insertion on about:-URLs

extensions/common/manifest_constants.cc

 // Copyright 2013 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 "extensions/common/manifest_constants.h"
 
 namespace extensions {
 
 namespace manifest_keys {
 
@@ skipping 232 matching lines @@
     "not been in invoked.";
 const char kAllURLOrActiveTabNeeded[] =
     "Either the '<all_urls>' or 'activeTab' permission is required.";
 const char kAppsNotEnabled[] =
     "Apps are not enabled.";
 const char kBackgroundPermissionNeeded[] =
     "Hosted apps that use 'background_page' must have the 'background' "
     "permission.";
 const char kBackgroundRequiredForPlatformApps[] =
     "Packaged apps must have a background page or background scripts.";
+const char kCannotAccessAboutUrl[] =
+    "Cannot access contents of url \"*\". Extension must have permission to "
+    "access the frame's origin, and matchAboutBlank must be true.";

[not at google - send to devlin, 2015/02/23 18:28:34]

Should this be "parent frame's origin" rather than "frame's origin"?

TBH I think these error messages are a bit wordy, e.g. "cannot access contents
of url blah" should just be "cannot access blah".

It'd also be nice to include what the parent frame's origin actually is in this
message.

[robwu, 2015/02/23 23:29:12]

Done.

 const char kCannotAccessChromeUrl[] = "Cannot access a chrome:// URL";
 const char kCannotAccessExtensionUrl[] =
     "Cannot access a chrome-extension:// URL of different extension";
 const char kCannotAccessPage[] =
     "Cannot access contents of url \"*\". "
     "Extension manifest must request permission to access this host.";
 const char kCannotChangeExtensionID[] =
     "Installed extensions cannot change their IDs.";
 const char kCannotClaimAllHostsInExtent[] =
     "Cannot claim all hosts ('*') in an extent.";
@@ skipping 427 matching lines @@
 const char kWebRequestConflictsWithLazyBackground[] =
     "The 'webRequest' API cannot be used with event pages.";
 #if defined(OS_CHROMEOS)
 const char kIllegalPlugins[] =
     "Extensions cannot install plugins on Chrome OS";
 #endif
 
 }  // namespace manifest_errors
 
 }  // namespace extensions