Propagate did_first_visually_non_empty_paint to the grpc client

Bug: None
Test: None
Change-Id: Ie720aa5c16971f0105504cb089e0b27a46c5d32e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1953670Reviewed-by: Daniel Nicoara <dnicoara@chromium.org>
Commit-Queue: Albert Chaulk <achaulk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#735084}

chromecast/browser/webview/webview_controller.cc

@@ -122,6 +122,18 @@ void WebviewController::ProcessRequest(const webview::WebviewRequest& request) {
   }
 }
 
+void WebviewController::DidFirstVisuallyNonEmptyPaint() {
+  if (client_) {
+    std::unique_ptr<webview::WebviewResponse> response =
+        std::make_unique<webview::WebviewResponse>();
+    auto* event = response->mutable_page_event();
+    event->set_url(contents_->GetURL().spec());
+    event->set_current_page_state(current_state());
+    event->set_did_first_visually_non_empty_paint(true);
+    client_->EnqueueSend(std::move(response));
+  }
+}
+
 void WebviewController::SendNavigationEvent(
     WebviewNavigationThrottle* throttle,
     content::NavigationHandle* navigation_handle) {

chromecast/browser/webview/webview_controller.h

@@ -72,6 +72,9 @@ class WebviewController : public CastWebContents::Delegate,
   // CastWebContents::Observer
   void ResourceLoadFailed(CastWebContents* cast_web_contents) override;
 
+  // content::WebContentsObserver
+  void DidFirstVisuallyNonEmptyPaint() override;
+
   std::unique_ptr<content::WebContents> contents_;
   std::unique_ptr<CastWebContents> cast_web_contents_;
   bool stopped_ = false;