Test that chrome.runtime.onMessage isn't fired for chrome.runtime.sendMessage

Test that chrome.runtime.onMessage isn't fired for chrome.runtime.sendMessage
sent from the same context.

This adds 2 tests, one that has always been the case, and a second regression
test which r325585 accidentally fixed.

BUG=479951
R=rdevlin.cronin@chromium.org

Committed: https://crrev.com/b9dca05429b19ad398d1dbf7496b44a94ba0f306
Cr-Commit-Position: refs/heads/master@{#327409}

[not at google - send to devlin, 2015-04-28 21:42:07]

https://codereview.chromium.org/1108203004/diff/1/chrome/test/data/extensions...
File chrome/test/data/extensions/api_test/messaging/connect/blank_frame.html
(right):

https://codereview.chromium.org/1108203004/diff/1/chrome/test/data/extensions...
chrome/test/data/extensions/api_test/messaging/connect/blank_frame.html:10: -->
FYI I will upload with --no-detect-copies or --no-find-copies or whatever it is
before submitting.

[Devlin, 2015-04-28 22:24:40]

lgtm

https://codereview.chromium.org/1108203004/diff/1/chrome/test/data/extensions...
File chrome/test/data/extensions/api_test/messaging/connect/test.js (right):

https://codereview.chromium.org/1108203004/diff/1/chrome/test/data/extensions...
chrome/test/data/extensions/api_test/messaging/connect/test.js:298: var
stopFailing = failWhileListening(chrome.runtime.onMessage);
nit: stopFailing is kinda a funny name...but I got nothin' better.

[not at google - send to devlin, 2015-04-28 22:46:31]

https://codereview.chromium.org/1108203004/diff/1/chrome/test/data/extensions...
File chrome/test/data/extensions/api_test/messaging/connect/test.js (right):

https://codereview.chromium.org/1108203004/diff/1/chrome/test/data/extensions...
chrome/test/data/extensions/api_test/messaging/connect/test.js:298: var
stopFailing = failWhileListening(chrome.runtime.onMessage);
On 2015/04/28 22:24:40, Devlin wrote:
> nit: stopFailing is kinda a funny name...but I got nothin' better.

I think of it like a function.

function stopFailing() {
  ...
}

makes perfect sense.

[not at google - send to devlin, 2015-04-28 22:47:01]

The CQ bit was checked by kalman@chromium.org

[not at google - send to devlin, 2015-04-28 22:47:01]

The patchset sent to the CQ was uploaded after l-g-t-m from
rdevlin.cronin@chromium.org
Link to the patchset: https://codereview.chromium.org/1108203004/#ps20001
(title: "no-copies")

[commit-bot: I haz the power, 2015-04-28 22:47:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1108203004/20001

[commit-bot: I haz the power, 2015-04-29 01:22:14]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-04-29 01:23:08]

Patchset 2 (id:??) landed as
https://crrev.com/b9dca05429b19ad398d1dbf7496b44a94ba0f306
Cr-Commit-Position: refs/heads/master@{#327409}