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

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

Currently, extension developers get the following message:
"Cannot access contents of url "about:blank". Extension manifest must
 request permission to access this host."

Extensions cannot request permission for about:-URLs, so this message is
useless. The message has been changed to: "Cannot access contents of url
"about:blank". Extension must have permission to access the frame's
origin, and matchAboutBlank must be true."

This message will be used in https://codereview.chromium.org/952473002/

R=kalman@chromium.org

Committed: https://crrev.com/a9e6e642db6fd06df8de455230b1057dc4e756a6
Cr-Commit-Position: refs/heads/master@{#322865}

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

lgtm

https://codereview.chromium.org/945743003/diff/1/extensions/common/manifest_c...
File extensions/common/manifest_constants.cc (right):

https://codereview.chromium.org/945743003/diff/1/extensions/common/manifest_c...
extensions/common/manifest_constants.cc:255: "access the frame's origin, and
matchAboutBlank must be true.";
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]

https://codereview.chromium.org/945743003/diff/1/extensions/common/manifest_c...
File extensions/common/manifest_constants.cc (right):

https://codereview.chromium.org/945743003/diff/1/extensions/common/manifest_c...
extensions/common/manifest_constants.cc:255: "access the frame's origin, and
matchAboutBlank must be true.";
On 2015/02/23 18:28:34, kalman wrote:
> 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.

Done.

[robwu, 2015-03-30 20:17:18]

The CQ bit was checked by rob@robwu.nl

[robwu, 2015-03-30 20:17:18]

The patchset sent to the CQ was uploaded after l-g-t-m from kalman@chromium.org
Link to the patchset: https://codereview.chromium.org/945743003/#ps20001 (title:
"Add origin to error message")

[commit-bot: I haz the power, 2015-03-30 20:17:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/945743003/20001

[commit-bot: I haz the power, 2015-03-30 21:14:14]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-03-30 21:14:54]

Patchset 2 (id:??) landed as
https://crrev.com/a9e6e642db6fd06df8de455230b1057dc4e756a6
Cr-Commit-Position: refs/heads/master@{#322865}