Added download error descriptions to tooltips for Mac & Linux.

chrome/browser/download/download_browsertest.cc

Index: chrome/browser/download/download_browsertest.cc
diff --git a/chrome/browser/download/download_browsertest.cc b/chrome/browser/download/download_browsertest.cc
index ad1dcdac0c697302b547ae60dc6881600c8e8dee..4ff3a5e3e9f035c5e8e3d4b69ee7fc2dedf1c0b8 100644
--- a/chrome/browser/download/download_browsertest.cc
+++ b/chrome/browser/download/download_browsertest.cc
@@ -790,6 +790,14 @@ class DownloadTest : public InProcessBrowserTest {
         }
       }
     }
+
+    MessageLoop::current()->PostDelayedTask(

[sky, 2012/04/04 16:55:34]

Don't post tasks of arbitrary length. It makes for flaky and long running tests.
Instead listen for whatever it is you need to then exit when you receive the
event.

[ahendrickson, 2012/04/04 17:49:32]

Oh, sorry, I intended to remove this.  It was only to see if I could see the
tooltips during a browser test (I couldn't).

Removed.

+        FROM_HERE,
+        base::Bind(&MessageLoop::Quit,
+                   base::Unretained(MessageLoop::current())),
+        5000);
+
+    ui_test_utils::RunMessageLoop();
   }
 
   // Attempts to download a set of files, based on information in the