Fix issues related to request and context object lifespan (issue #1037, issue #1044).

- Simplify and document the relationship between the various context object types. See browser_context.h for a description of the new relationships.
- cefclient: Add `request-context-per-browser` command-line flag for testing multiple CefRequestContext instances.
- cefclient: Add a CefURLRequest example.

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@2032 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

tests/cefclient/browser/osr_window_win.h

@@ -48,6 +48,7 @@ class OsrWindowWin :
                      const RECT& rect,
                      CefRefPtr<CefClient> handler,
                      const CefBrowserSettings& settings,
+                     CefRefPtr<CefRequestContext> request_context,
                      const std::string& startup_url);
   
   // Show the popup window with correct parent and bounds in parent coordinates.