Add helper method to check for invalid message source.

Add helper method to check for invalid message source.

This CL refactors the check for invalid render_frame_message_source_ to a common method and uses it in all of the relevant IPC handlers. Ideally it will all be removed once RenderViewHost disappears or all of its IPC handling is removed.

BUG=451932, 449777
Committed: https://crrev.com/907fcb65c9ff242000395d8e4483ebdca8b77cbe
Cr-Commit-Position: refs/heads/master@{#313445}

[nasko, 2015-01-27 22:42:13]

nasko@chromium.org changed reviewers:
+ creis@chromium.org

[nasko, 2015-01-27 22:42:13]

Hey Charlie,
Can you review this CL for me? It refactors the render_frame_message_source_
checks into a common method and uses it in all cases.
Thanks in advance!
Nasko

[Charlie Reis, 2015-01-27 23:16:18]

Great.  LGTM with nit.

https://codereview.chromium.org/877203002/diff/1/content/browser/web_contents...
File content/browser/web_contents/web_contents_impl.cc (right):

https://codereview.chromium.org/877203002/diff/1/content/browser/web_contents...
content/browser/web_contents/web_contents_impl.cc:572: if
(!render_frame_message_source_) {
nit: As long as we're making this a helper method, let's make the motivation for
killing the top-level process a little clearer by adding:

DCHECK(render_view_message_source_);

(I think DCHECK is better than CHECK here, since it's mainly documenting that we
don't expect this to fail, without needing it to be strictly enforced.)

[nasko, 2015-01-28 02:20:10]

https://codereview.chromium.org/877203002/diff/1/content/browser/web_contents...
File content/browser/web_contents/web_contents_impl.cc (right):

https://codereview.chromium.org/877203002/diff/1/content/browser/web_contents...
content/browser/web_contents/web_contents_impl.cc:572: if
(!render_frame_message_source_) {
On 2015/01/27 23:16:17, Charlie Reis (slow until 1-29) wrote:
> nit: As long as we're making this a helper method, let's make the motivation
for
> killing the top-level process a little clearer by adding:
> 
> DCHECK(render_view_message_source_);
> 
> (I think DCHECK is better than CHECK here, since it's mainly documenting that
we
> don't expect this to fail, without needing it to be strictly enforced.)

Done.

[nasko, 2015-01-28 02:20:17]

The CQ bit was checked by nasko@chromium.org

[commit-bot: I haz the power, 2015-01-28 02:21:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/877203002/20001

[commit-bot: I haz the power, 2015-01-28 04:24:40]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-01-28 04:25:49]

Patchset 2 (id:??) landed as
https://crrev.com/907fcb65c9ff242000395d8e4483ebdca8b77cbe
Cr-Commit-Position: refs/heads/master@{#313445}