Add test: PostMessage from unload handler to its remote parent.

+ SitePerProcessBrowserTest.UnloadPostMessageToParentCrossProcess
+ SitePerProcessBrowserTest.UnloadPostMessageToParentSameProcess

Unloading document must be able to postMessage to its living parent.
The same process case works fine. The cross process doesn't because postMessage
is send to a task runner and so executed after sending the FrameHostMsg_Detach.

Bug: 964950
Change-Id: I346b7bb17e778a8fe2f05c3964caef02894e9ad5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1617460
Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#661661}
1 file changed