Do not reset controller when web contents destroyed

This instead calls OnError to allow for proper cleanup
when web contents destruction occurs.

Bug: Internal b/146500172
Test: Build cast_shell
Change-Id: I4c83313c8324e361cdb0a0275bfa76ea1a5ae72b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1985810
Commit-Queue: Shawn Gallea <sagallea@google.com>
Reviewed-by: Daniel Nicoara <dnicoara@chromium.org>
Cr-Commit-Position: refs/heads/master@{#733468}

chromecast/browser/webview/cast_app_controller.cc

@@ -34,4 +34,8 @@ content::WebContents* CastAppController::GetWebContents() {
   return contents_;
 }
 
+void CastAppController::WebContentsDestroyed() {
+  contents_ = nullptr;
+}
+
 }  // namespace chromecast

chromecast/browser/webview/cast_app_controller.h

@@ -22,6 +22,9 @@ class CastAppController : public WebContentController {
   content::WebContents* GetWebContents() override;
 
  private:
+  // content::WebContentsObserver
+  void WebContentsDestroyed() override;
+
   content::WebContents* contents_;
 
   DISALLOW_COPY_AND_ASSIGN(CastAppController);

chromecast/browser/webview/cast_app_rpc_instance.cc

@@ -68,8 +68,8 @@ void CastAppRpcInstance::CreateCastAppWindowLink(int platform_view_id,
 }
 
 void CastAppRpcInstance::WebContentsDestroyed() {
-  controller_.reset();
   window_manager_->RemoveObserver(this);
+  OnError("Web contents destroyed");
 }
 
 }  // namespace chromecast

chromecast/browser/webview/platform_views_rpc_instance.cc

@@ -59,7 +59,8 @@ void PlatformViewsRpcInstance::OnError(const std::string& error_message) {
 
 void PlatformViewsRpcInstance::ProcessRequestOnControllerThread(
     std::unique_ptr<webview::WebviewRequest> request) {
-  controller_->ProcessRequest(*request.get());
+  if (!errored_)
+    controller_->ProcessRequest(*request.get());
 }
 
 void PlatformViewsRpcInstance::InitComplete(bool ok) {

chromecast/browser/webview/web_content_controller.cc

@@ -406,7 +406,11 @@ void WebContentController::HandleSetAutoMediaPlaybackPolicy(
 }
 
 viz::SurfaceId WebContentController::GetSurfaceId() {
-  auto* rwhv = GetWebContents()->GetRenderWidgetHostView();
+  content::WebContents* web_contents = GetWebContents();
+  // Web contents are destroyed before controller for cast apps.
+  if (!web_contents)
+    return viz::SurfaceId();
+  auto* rwhv = web_contents->GetRenderWidgetHostView();
   if (!rwhv)
     return viz::SurfaceId();
   auto frame_sink_id = rwhv->GetRenderWidgetHost()->GetFrameSinkId();