Add AssertNoURLRequests() to URLRequestContext subclass destructors.

chrome/browser/io_thread.cc

Index: chrome/browser/io_thread.cc
diff --git a/chrome/browser/io_thread.cc b/chrome/browser/io_thread.cc
index 2a116ed77554707c3dab8c12be04f089de4ed2fc..9e7f086981092481630ee9986c485e4e39c6228a 100644
--- a/chrome/browser/io_thread.cc
+++ b/chrome/browser/io_thread.cc
@@ -159,6 +159,7 @@ class SystemURLRequestContext : public net::URLRequestContext {
 
  private:
   virtual ~SystemURLRequestContext() {
+    AssertNoURLRequests();

[Ryan Sleevi, 2014/07/10 16:49:19]

Seems like this should go second, right?

After all, what if line 164 cancels requests?

[Johnny, 2014/07/10 16:58:28]

That'd be a violation of the URLRequestContext lifetime invariant. URLRequests
must keep a URLRequestContext alive, not the other way around, no?

(It doesn't, btw. Just sets a global).

 #if defined(USE_NSS) || defined(OS_IOS)
     net::SetURLRequestContextForNSSHttpIO(NULL);
 #endif