Give the main frame a RenderWidget.
Currently, RenderView is a subclass of RenderWidget, and the RenderWidget
portion is effectively treated as the the widget for the main frame as
well. For a number of reasons, this is a problematic model:
- A remote frame doesn't need a widget; however, a RenderView with a remote
main frame still has a vestigal RenderWidget.
- Code that needs to affect both RenderWidget / RenderView is awkwardly
split between them, in both content and blink.
- RenderView itself is often seen as an easy entry point to perform
page-level work in the renderer. With OOPI, this is no longer a valid
assumption.
In order to incrementally de-widgetize RenderView, the main frame will
have also have a RenderWidget, to make it consistent with the local frame
roots for subframes, which already have a RenderWidget. However, instead of
giving main frames their own RenderWidget, the main frame re-uses the
RenderView as its RenderWidget.
The rationale for taking this approach is to minimize the breakage: today,
Chrome simply doesn't expect to have two "widgets" for a frame.
Instantiating a distinct RenderWidget for the main frame can confuse code
that iterates or counts the active widgets: an example of this is the
security check for injecting WebUI bindings.
In the future, when RenderViewHost has-a RenderWidgetHost (and similarly,
when RenderViewImpl has-a RenderWidget) instead of today's is-a relation,
then it be conceptually much more straightforward to transition completely
to the new model.
BUG=419087
Review URL: https://codereview.chromium.org/1303773002
Cr-Commit-Position: refs/heads/master@{#356176}
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index 35da9b59..d9d9d20 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -491,8 +491,9 @@
void LostMouseLock() override;
void CreateNewWindow(
SiteInstance* source_site_instance,
- int route_id,
- int main_frame_route_id,
+ int32_t route_id,
+ int32_t main_frame_route_id,
+ int32_t main_frame_widget_route_id,
const ViewHostMsg_CreateWindow_Params& params,
SessionStorageNamespace* session_storage_namespace) override;
void CreateNewWidget(int32 render_process_id,
