MacViews: Disable PluginDiscovery in views_examples_with_content_exe

MacViews: Disable PluginDiscovery in views_examples_with_content_exe

TransformPathForFeature in child_process_host_impl.cc expects to find
`Chromium Helper XX` inside the .app bundle, but
views_examples_with_content_exe is a standalone executable. The example
app doesn't need plugins so this CL disables plugin discovery to avoid:

Check failed: kMacOSName == macos_path.BaseName().value() (MacOS vs.
Debug)

This occurs when particular pages are loaded in the WebView example,
triggered via content::PluginLoaderPosix::LoadPluginsInternal().

The change is made in views_content_client, which affects app_list_demo
and views_examples_with_content_exe.

BUG=395507
Committed: https://crrev.com/9f1e45ad728dc3a236798f55abb677f473a47097
Cr-Commit-Position: refs/heads/master@{#299392}

[tapted, 2014-10-13 22:31:55]

tapted@chromium.org changed reviewers:
+ avi@chromium.org

[tapted, 2014-10-13 22:31:55]

Hi Avi - WDYT? This is currently only used by 2 example exes. Other options
could be to try to tackle it in content/common/child_process_host_impl.cc, or
have the example main() function set an option for `views_content_client`

[Avi (use Gerrit), 2014-10-13 22:37:21]

Well, that's one way to do it.

My normal argument would be that we should be properly bundling these sample
apps rather than letting them run on the commandline, but I think my hatred for
plugins runs even deeper.

If this makes your life easier for now, LGTM, but you may want to return to
rethink packaging later.

[tapted, 2014-10-13 22:56:20]

:) Thanks avi! On packaging, I agree - if these get much more complicated I'll
probably be looking into that (maybe at a time when I can make an elegant
generic solution for it in gn..).

[tapted, 2014-10-13 22:56:30]

The CQ bit was checked by tapted@chromium.org

[commit-bot: I haz the power, 2014-10-13 22:57:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/655433002/1

[commit-bot: I haz the power, 2014-10-13 23:36:16]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-13 23:37:14]

Patchset 1 (id:??) landed as
https://crrev.com/9f1e45ad728dc3a236798f55abb677f473a47097
Cr-Commit-Position: refs/heads/master@{#299392}