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/browser_window.h

@@ -46,7 +46,8 @@ class BrowserWindow : public ClientHandler::Delegate {
   // Create a new browser and native window.
   virtual void CreateBrowser(ClientWindowHandle parent_handle,
                              const CefRect& rect,
-                             const CefBrowserSettings& settings) = 0;
+                             const CefBrowserSettings& settings,
+                             CefRefPtr<CefRequestContext> request_context) = 0;
 
   // Retrieve the configuration that will be used when creating a popup window.
   // The popup browser will initially be parented to |temp_handle| which should