Factor out RenderWidgetHostConnector

content/browser/android/render_widget_host_connector.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/browser/android/render_widget_host_connector.h"
+
+#include "content/browser/frame_host/interstitial_page_impl.h"
+#include "content/browser/renderer_host/render_widget_host_view_android.h"
+#include "content/browser/web_contents/web_contents_impl.h"
+
+namespace content {
+
+RenderWidgetHostConnector::Observer::Observer(
+    WebContents* web_contents,
+    RenderWidgetHostConnector* connector)
+    : WebContentsObserver(web_contents),
+      connector_(connector),
+      rwhva_(nullptr) {}
+
+RenderWidgetHostConnector::Observer::~Observer() {}
+
+void RenderWidgetHostConnector::Observer::RenderViewHostChanged(
+    RenderViewHost* old_host,
+    RenderViewHost* new_host) {
+  auto* old_view = old_host ? static_cast<RenderWidgetHostViewAndroid*>(
+                                  old_host->GetWidget()->GetView())
+                            : nullptr;

[boliu, 2017/04/13 21:26:59]

Like I said earlier, UpdateRenderWidgetHostView is always a transition, where
old_rwhva is always equal to the *previous* new_rwhva. I'm not sure that
condition holds here with interstitials, ie if you can DCHECK old_view and
rwhva_ always matches, or if this needs to be dealt with explicitly

[Jinsuk Kim, 2017/04/13 23:00:43]

It holds true for interstitials too. Put DCHECK.

+  auto* new_view = new_host ? static_cast<RenderWidgetHostViewAndroid*>(
+                                  new_host->GetWidget()->GetView())
+                            : nullptr;
+  UpdateRenderWidgetHostView(old_view, new_view);
+}
+
+void RenderWidgetHostConnector::Observer::DidAttachInterstitialPage() {
+  UpdateRenderWidgetHostView(rwhva_, GetRenderWidgetHostViewAndroid());
+}
+
+void RenderWidgetHostConnector::Observer::DidDetachInterstitialPage() {
+  UpdateRenderWidgetHostView(rwhva_, GetRenderWidgetHostViewAndroid());
+}
+
+void RenderWidgetHostConnector::Observer::WebContentsDestroyed() {
+  UpdateRenderWidgetHostView(GetRenderWidgetHostViewAndroid(), nullptr);
+  delete connector_;
+}
+
+void RenderWidgetHostConnector::Observer::RenderWidgetHostViewDestroyed(
+    RenderWidgetHostViewAndroid* destroyed_rwhva) {
+  if (rwhva_ == destroyed_rwhva) {
+    // Null out the raw pointers here and in the connector impl to keep
+    // them from referencing the rwvha about to be destroyed.
+    connector_->UpdateRenderProcessConnection(rwhva_, nullptr);
+    rwhva_ = nullptr;
+  }
+}
+
+void RenderWidgetHostConnector::Observer::UpdateRenderWidgetHostView(
+    RenderWidgetHostViewAndroid* old_rwhva,
+    RenderWidgetHostViewAndroid* new_rwhva) {
+  if (old_rwhva == new_rwhva)
+    return;
+  if (old_rwhva)
+    old_rwhva->RemoveDestructionObserver(this);
+  if (new_rwhva)
+    new_rwhva->AddDestructionObserver(this);
+
+  connector_->UpdateRenderProcessConnection(old_rwhva, new_rwhva);
+  rwhva_ = new_rwhva;
+}
+
+RenderWidgetHostViewAndroid*
+RenderWidgetHostConnector::Observer::GetRenderWidgetHostViewAndroid() const {
+  RenderWidgetHostView* rwhv = web_contents()->GetRenderWidgetHostView();
+  WebContentsImpl* web_contents_impl =
+      static_cast<WebContentsImpl*>(web_contents());
+  if (web_contents_impl->ShowingInterstitialPage()) {
+    rwhv = web_contents_impl->GetInterstitialPage()
+               ->GetMainFrame()
+               ->GetRenderViewHost()
+               ->GetWidget()
+               ->GetView();
+  }
+  return static_cast<RenderWidgetHostViewAndroid*>(rwhv);
+}
+
+RenderWidgetHostConnector::RenderWidgetHostConnector(WebContents* web_contents)
+    : render_widget_observer_(new Observer(web_contents, this)) {}
+
+RenderWidgetHostConnector::~RenderWidgetHostConnector() {}
+
+}  // namespace content