Revert 133359 - Relanding r133313.

I've reordered the resource request URLRequest cancellations so now I can reland r133313 and not have it assert on renderer resource requests.

==========

Revert 133313 - I need to move the assertion to a better place.

Assert when URLRequests leak for the main URLRequestContexts.

I've already enabled the assertions for all the non-main URLRequestContexts:
  * safe browsing
  * system
  * media
  * extensions

I've squashed those leaks, so now it's time to work on the main URLRequestContext for the profile. I know there are defintely existing l

BUG=90971
TEST=none

==========

TBR=eroman
BUG=90971
TEST=none


Review URL: http://codereview.chromium.org/10219010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@133842 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/profiles/profile_io_data.cc

@@ -267,12 +267,8 @@ ProfileIOData::~ProfileIOData() {
   if (BrowserThread::IsMessageLoopValid(BrowserThread::IO))
     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
-#if 0
-  // TODO(willchan): If I am ever able to enable this assertion and have it
-  // stick, I'm going to party like it's 2008.
   if (main_request_context_)
     main_request_context_->AssertNoURLRequests();
-#endif
   if (extensions_request_context_)
     extensions_request_context_->AssertNoURLRequests();
   for (AppRequestContextMap::iterator it = app_request_context_map_.begin();