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_osr_mac.mm

@@ -1100,9 +1100,11 @@ BrowserWindowOsrMac::~BrowserWindowOsrMac() {
   }
 }
 
-void BrowserWindowOsrMac::CreateBrowser(ClientWindowHandle parent_handle,
-                                        const CefRect& rect,
-                                        const CefBrowserSettings& settings) {
+void BrowserWindowOsrMac::CreateBrowser(
+    ClientWindowHandle parent_handle,
+    const CefRect& rect,
+    const CefBrowserSettings& settings,
+    CefRefPtr<CefRequestContext> request_context) {
   REQUIRE_MAIN_THREAD();
 
   // Create the native NSView.
@@ -1114,7 +1116,7 @@ void BrowserWindowOsrMac::CreateBrowser(ClientWindowHandle parent_handle,
   // Create the browser asynchronously.
   CefBrowserHost::CreateBrowser(window_info, client_handler_,
                                 client_handler_->startup_url(),
-                                settings, NULL);
+                                settings, request_context);
 }
 
 void BrowserWindowOsrMac::GetPopupConfig(CefWindowHandle temp_handle,