Remove several unnecessary guest view owner WebContents accesses

In each of these cases, accessing the owner RFH is enough.

Bug: 1261928
Change-Id: Ibe1cf569cdec580760e6a8752966df0c1240fdec
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4843546
Commit-Queue: James Maclean <wjmaclean@chromium.org>
Auto-Submit: Kevin McNee <mcnee@chromium.org>
Reviewed-by: James Maclean <wjmaclean@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1192981}

chrome/browser/guest_view/web_view/context_menu_content_type_web_view.cc

@@ -62,7 +62,7 @@ bool ContextMenuContentTypeWebView::SupportsGroup(int group) {
         // For a list of places where <webview>/GuestViews are supported, see:
         // https://goo.gl/xfJkwp.
         if (!embedder_extension && web_view_guest_ &&
-            web_view_guest_->owner_web_contents()->GetWebUI()) {
+            web_view_guest_->owner_rfh()->GetMainFrame()->GetWebUI()) {
           return false;
         }
       }

extensions/browser/guest_view/app_view/app_view_guest.cc

@@ -256,7 +256,7 @@ void AppViewGuest::CompleteCreateWebContents(
     const Extension* guest_extension,
     std::unique_ptr<GuestViewBase> owned_this,
     WebContentsCreatedCallback callback) {
-  if (!owner_web_contents()) {
+  if (!owner_rfh()) {
     // The owner was destroyed before getting a response to the embedding
     // request, so we can't proceed with creating a guest.
     std::move(callback).Run(std::move(owned_this), nullptr);

extensions/browser/guest_view/web_view/web_view_guest.cc

@@ -332,8 +332,7 @@ int WebViewGuest::GetOrGenerateRulesRegistryID(int embedder_process_id,
 void WebViewGuest::CreateWebContents(std::unique_ptr<GuestViewBase> owned_this,
                                      const base::Value::Dict& create_params,
                                      WebContentsCreatedCallback callback) {
-  RenderFrameHost* owner_render_frame_host =
-      owner_web_contents()->GetPrimaryMainFrame();
+  RenderFrameHost* owner_render_frame_host = owner_rfh();
   RenderProcessHost* owner_render_process_host =
       owner_render_frame_host->GetProcess();
   DCHECK_EQ(browser_context(), owner_render_process_host->GetBrowserContext());
@@ -833,10 +832,10 @@ void WebViewGuest::DidFinishNavigation(
     content::NavigationHandle* navigation_handle) {
   if (navigation_handle->IsErrorPage() || !navigation_handle->HasCommitted()) {
     // Suppress loadabort for "mailto" URLs.
-    // Also during destruction, owner_web_contents() is null so there's no point
+    // Also during destruction, the owner is null so there's no point
     // trying to send the event.
     if (!navigation_handle->GetURL().SchemeIs(url::kMailToScheme) &&
-        owner_web_contents()) {
+        owner_rfh()) {
       // If a load is blocked, either by WebRequest or security checks, the
       // navigation may or may not have committed. So if we don't see an error
       // code, mark it as blocked.