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

extensions/common/manifest_constants.cc

Index: extensions/common/manifest_constants.cc
diff --git a/extensions/common/manifest_constants.cc b/extensions/common/manifest_constants.cc
index 1c51334cba975b42b1c3a280e75023ef7179c875..a94810b0a93c6bc0ec6fb7ca966b70fb52aea018 100644
--- a/extensions/common/manifest_constants.cc
+++ b/extensions/common/manifest_constants.cc
@@ -250,6 +250,9 @@ const char kBackgroundPermissionNeeded[] =
     "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";