Fix some typos, broken links and other issues in extension docs

chrome/common/extensions/api/downloads.idl

Index: chrome/common/extensions/api/downloads.idl
===================================================================
--- chrome/common/extensions/api/downloads.idl	(revision 181647)
+++ chrome/common/extensions/api/downloads.idl	(working copy)
@@ -191,8 +191,7 @@
     // with a hyphen: '-startTime'.
     DOMString? orderBy;
 
-    // The <code>id</code> of the $ref:DownloadItem
-    // that changed.
+    // An identifier that is persistent across browser sessions.

[Randy Smith (Not in Mondays), 2013/02/11 16:35:02]

Why are you changing this text?  As I read it, this comment is a back-reference
to the description of id in DownloadItem above, and as such the original text
makes more sense to me.

[not at google - send to devlin, 2013/02/11 16:37:13]

The original text seems wrong, and supposed to be on DownloadDelta (as moved) -
but you're right, something like "The <code>id</code> of the DownloadItem to
query" would be better.

     long? id;
 
     // Absolute URL.
@@ -259,7 +258,8 @@
 
   // Encapsulates a change in a DownloadItem.
   [inline_doc] dictionary DownloadDelta {
-    // An identifier that is persistent across browser sessions.
+    // The <code>id</code> of the $ref:DownloadItem
+    // that changed.
     long id;
 
     // The change in <code>url</code>, if any.