What plugin is Google Chrome blocking?

In Google Chrome, I have my options set so that all plugins are click-to-play. For the most part, this works fine. However, sometimes, Chrome will show the on a page that I can't find a plugin on, even by looking through the source html of the page. There's no element on the page that I can see that is asking me to click it to play the plugin. Is there a way to identify exactly what plugin(s) Google is asking me to play?

I'm aware that I can go through and disable extensions to see if one of those is causing it, but in general, it'd be nice to know what I'm enabling when I run plugins, so I'd still like to know if there is a way to identify them.

Note: These settings can be obtained by the following steps:

1. about:flags > disable Block all third-party cookies
2. options > Under the Hood > Plugins > Click To Play

You should be able to find them by looking through the embed tags and perhaps the newer canvas tags.

1. Start the Developer tools from the Wrench -> Tools menu.

2. Search for embed and canvas, enumerate through the found tags.

3. Repeat the search for both the Elements and Scripts tab.

In my case I have Cooliris installed, and apparently thanks to you I have just discovered that it always loads:

_{PS: I'm using Firefox 6.0a1 as a main browser, but Google Chrome and IE9 as a back-up for when Firefox 6.0a1 breaks.}

However, if enabling the plug-in is allowed, you could simply open Task Manager from the Tools menu and check the latest plug-in(s) that was/were launched. Which indicates what plug-in(s) the site ran.