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

chrome/common/extensions/api/downloads.idl

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 [permissions=downloads]
 namespace downloads {
   [inline_doc] dictionary HeaderNameValuePair {
     // Name of the HTTP header.
     DOMString name;
 
@@ skipping 173 matching lines @@
 
     // Setting this string to a $ref:DownloadItem
     // property sorts the $ref:DownloadItem prior
     // to applying the above filters. For example, setting
     // <code>orderBy='startTime'</code> sorts the
     // $ref:DownloadItem by their start time in
     // ascending order. To specify descending order, prefix <code>orderBy</code>
     // 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.
     DOMString? url;
 
     // Absolute local path.
     DOMString? filename;
 
     // Indication of whether this download is thought to be safe or known to be
     // suspicious.
@@ skipping 46 matching lines @@
     long? current;
   };
 
   [inline_doc] dictionary DownloadBooleanDiff {
     boolean? previous;
     boolean? current;
   };
 
   // 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.
     DownloadStringDiff? url;
 
     // The change in <code>filename</code>, if any.
     DownloadStringDiff? filename;
 
     // The change in <code>danger</code>, if any.
     DownloadStringDiff? danger;
@@ skipping 149 matching lines @@
     // history.
     // |downloadId|: The <code>id</code> of the $ref:DownloadItem that was erased.
     static void onErased(long downloadId);
 
     // When any of a $ref:DownloadItem's properties
     // except <code>bytesReceived</code> changes, this event fires with the
     // <code>downloadId</code> and an object containing the properties that changed.
     static void onChanged(DownloadDelta downloadDelta);
   };
 };