Make it harder to construct the wrong kind of WebFrameWidget.

Current, there's a different internal implementation of WebFrameWidget
for main frames, to disguise the fact that WebView happens to be a
WebWidget as well.

Rather than exposing this implementation detail, just make the Create()
function do the right thing.

TBR=thestig@chromium.org

Change-Id: Ic6c5701953b16350ddbc927fb6355956d5724b54
Reviewed-on: https://chromium-review.googlesource.com/538737
Commit-Queue: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#480299}

components/plugins/renderer/webview_plugin.cc

@@ -262,9 +262,7 @@ WebViewPlugin::WebViewHelper::WebViewHelper(
   WebLocalFrame* web_frame = WebLocalFrame::Create(
       blink::WebTreeScopeType::kDocument, this, nullptr, nullptr);
   web_view_->SetMainFrame(web_frame);
-  // TODO(dcheng): The main frame widget currently has a special case.
-  // Eliminate this once WebView is no longer a WebWidget.
-  WebFrameWidget::Create(this, web_view_, web_frame);
+  WebFrameWidget::Create(this, web_frame);
 }
 
 WebViewPlugin::WebViewHelper::~WebViewHelper() {

components/printing/renderer/print_web_view_helper.cc

@@ -586,7 +586,7 @@ void PrintWebViewHelper::PrintHeaderAndFooter(
       blink::WebTreeScopeType::kDocument, &frame_client, nullptr, nullptr);
   web_view->SetMainFrame(frame);
   blink::WebWidgetClient web_widget_client;
-  blink::WebFrameWidget::Create(&web_widget_client, web_view, frame);
+  blink::WebFrameWidget::Create(&web_widget_client, frame);
 
   base::Value html(
       base::UTF8ToUTF16(ResourceBundle::GetSharedInstance().GetRawDataResource(
@@ -808,7 +808,7 @@ void PrepareFrameAndViewForPrint::CopySelection(
   blink::WebLocalFrame* main_frame = blink::WebLocalFrame::Create(
       blink::WebTreeScopeType::kDocument, this, nullptr, nullptr);
   web_view->SetMainFrame(main_frame);
-  blink::WebFrameWidget::Create(this, web_view, main_frame);
+  blink::WebFrameWidget::Create(this, main_frame);
   frame_.Reset(web_view->MainFrame()->ToWebLocalFrame());
   node_to_print_.Reset();
 

content/renderer/render_widget.cc

@@ -489,11 +489,6 @@ RenderWidget* RenderWidget::CreateForFrame(
 blink::WebFrameWidget* RenderWidget::CreateWebFrameWidget(
     RenderWidget* render_widget,
     blink::WebLocalFrame* frame) {
-  if (!frame->Parent()) {
-    // TODO(dcheng): The main frame widget currently has a special case.
-    // Eliminate this once WebView is no longer a WebWidget.
-    return blink::WebFrameWidget::Create(render_widget, frame->View(), frame);
-  }
   return blink::WebFrameWidget::Create(render_widget, frame);
 }
 

third_party/WebKit/Source/core/frame/FrameTestHelpers.cpp

@@ -264,10 +264,7 @@ WebViewBase* WebViewHelper::InitializeWithOpener(
       web_frame_client->GetInterfaceProviderForTesting(), nullptr, opener);
   web_frame_client->Bind(frame, std::move(owned_web_frame_client));
   web_view_->SetMainFrame(frame);
-
-  // TODO(dcheng): The main frame widget currently has a special case.
-  // Eliminate this once WebView is no longer a WebWidget.
-  blink::WebFrameWidget::Create(web_widget_client, web_view_, frame);
+  blink::WebFrameWidget::Create(web_widget_client, frame);
 
   test_web_view_client_ = web_view_client;
 

third_party/WebKit/Source/web/WebFrameWidgetImpl.cpp

@@ -83,16 +83,22 @@ namespace blink {
 WebFrameWidget* WebFrameWidget::Create(WebWidgetClient* client,
                                        WebLocalFrame* local_root) {
   DCHECK(client) << "A valid WebWidgetClient must be supplied.";
-  // Pass the WebFrameWidget's self-reference to the caller.
-  return WebFrameWidgetImpl::Create(client, local_root);
-}
+  if (!local_root->Parent()) {
+    // Note: this isn't a leak, as the object has a self-reference that the
+    // caller needs to release by calling Close().
+    WebLocalFrameBase& main_frame = ToWebLocalFrameBase(*local_root);
+    DCHECK(main_frame.ViewImpl());
+    // Note: this can't DCHECK that the view's main frame points to
+    // |main_frame|, as provisional frames violate this precondition.
+    // TODO(dcheng): Remove the special bridge class for main frame widgets.
+    return new WebViewFrameWidget(*client, *main_frame.ViewImpl(), main_frame);
+  }
 
-WebFrameWidget* WebFrameWidget::Create(WebWidgetClient* client,
-                                       WebView* web_view,
-                                       WebLocalFrame* main_frame) {
-  DCHECK(client) << "A valid WebWidgetClient must be supplied.";
-  return new WebViewFrameWidget(*client, static_cast<WebViewBase&>(*web_view),
-                                ToWebLocalFrameBase(*main_frame));
+  DCHECK(local_root->Parent()->IsWebRemoteFrame())
+      << "Only local roots can have web frame widgets.";
+  // Note: this isn't a leak, as the object has a self-reference that the
+  // caller needs to release by calling Close().
+  return WebFrameWidgetImpl::Create(client, local_root);
 }
 
 WebFrameWidgetImpl* WebFrameWidgetImpl::Create(WebWidgetClient* client,

third_party/WebKit/Source/web/tests/WebViewTest.cpp

@@ -2064,10 +2064,7 @@ TEST_P(WebViewTest, ClientTapHandlingNullWebViewClient) {
       WebTreeScopeType::kDocument, &web_frame_client, nullptr, nullptr);
   web_frame_client.Bind(local_frame);
   web_view->SetMainFrame(local_frame);
-
-  // TODO(dcheng): The main frame widget currently has a special case.
-  // Eliminate this once WebView is no longer a WebWidget.
-  blink::WebFrameWidget::Create(&web_widget_client, web_view, local_frame);
+  blink::WebFrameWidget::Create(&web_widget_client, local_frame);
 
   WebGestureEvent event(WebInputEvent::kGestureTap, WebInputEvent::kNoModifiers,
                         WebInputEvent::kTimeStampForTesting);

third_party/WebKit/public/web/WebFrameWidget.h

@@ -41,18 +41,11 @@ namespace blink {
 class WebDragData;
 class WebLocalFrame;
 class WebInputMethodController;
-class WebView;
 class WebWidgetClient;
 
 class WebFrameWidget : public WebWidget {
  public:
   BLINK_EXPORT static WebFrameWidget* Create(WebWidgetClient*, WebLocalFrame*);
-  // Creates a frame widget for a WebView. Temporary helper to help transition
-  // away from WebView inheriting WebWidget.
-  // TODO(dcheng): Remove once transition is complete.
-  BLINK_EXPORT static WebFrameWidget* Create(WebWidgetClient*,
-                                             WebView*,
-                                             WebLocalFrame* main_frame);
 
   // Sets the visibility of the WebFrameWidget.
   // We still track page-level visibility, but additionally we need to notify a