Update to Chromium revision 304f01a1 (#358063)

- Improve ordering of CefLoadHandler callbacks. OnLoadingStateChange will
  be called before and after all calls to OnLoadStart and OnLoadEnd.
  OnLoadStart/OnLoadEnd calls will occur as matching pairs
  (see http://crbug.com/539952#c2).
- Remove the |requesting_url| argument to CefGeolocationHandler::
  OnCancelGeolocationPermission. Clients can use the |request_id| argument
  to track this information themselves.
- Fix a crash when loading the PDF extension in multiple browsers with a
  custom CefRequestContext (issue #1757).

libcef/browser/extensions/extensions_api_client.cc

@@ -6,6 +6,7 @@
 #include "libcef/browser/extensions/extensions_api_client.h"
 
 #include "include/internal/cef_types_wrappers.h"
+#include "libcef/browser/browser_context_impl.h"
 #include "libcef/browser/extensions/extension_web_contents_observer.h"
 #include "libcef/browser/extensions/mime_handler_view_guest_delegate.h"
 #include "libcef/browser/extensions/pdf_web_contents_helper_client.h"
@@ -13,6 +14,7 @@
 
 #include "chrome/browser/ui/prefs/prefs_tab_helper.h"
 #include "components/pdf/browser/pdf_web_contents_helper.h"
+#include "extensions/browser/guest_view/extensions_guest_view_manager_delegate.h"
 
 namespace extensions {
 
@@ -26,6 +28,22 @@ AppViewGuestDelegate* CefExtensionsAPIClient::CreateAppViewGuestDelegate()
   return NULL;
 }
 
+scoped_ptr<guest_view::GuestViewManagerDelegate>
+CefExtensionsAPIClient::CreateGuestViewManagerDelegate(
+    content::BrowserContext* context) const {
+  // The GuestViewManager instance associated with the returned Delegate, which
+  // will be retrieved in the future via GuestViewManager::FromBrowserContext,
+  // will be associated with the CefBrowserContextImpl instead of |context| due
+  // to ShouldProxyUserData in browser_context_proxy.cc. Because the
+  // GuestViewManagerDelegate keeps a reference to the passed-in context we need
+  // to provide the *Impl object instead of |context| which may be a *Proxy
+  // object. If we don't do this then the Delegate may attempt to access a
+  // *Proxy object that has already been deleted.
+  return make_scoped_ptr(
+      new extensions::ExtensionsGuestViewManagerDelegate(
+          CefBrowserContextImpl::GetForContext(context).get()));
+}
+
 scoped_ptr<MimeHandlerViewGuestDelegate>
 CefExtensionsAPIClient::CreateMimeHandlerViewGuestDelegate(
     MimeHandlerViewGuest* guest) const {