[Chromecast] Disable supports_multiple_windows to Webviews

This change disables supports_multiple_windows by default to
Webview controller, in order to open new window navigations
in the current view.

Bug: b/170218696
Test: Sample website on Chromecast navigates on the current view.
Change-Id: I44cb7d7e9c8ffa42789f7019779fc9c87935ba92
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2533679Reviewed-by: Sean Topping <seantopping@chromium.org>
Reviewed-by: Daniel Nicoara <dnicoara@chromium.org>
Commit-Queue: Jiaqi Han <jiaqih@google.com>
Cr-Commit-Position: refs/heads/master@{#827432}

chromecast/browser/cast_content_browser_client.cc

@@ -694,6 +694,22 @@ bool CastContentBrowserClient::CanCreateWindow(
     bool opener_suppressed,
     bool* no_javascript_access) {
   *no_javascript_access = true;
+
+  // To show new page in the existing view for WebView new window navigations,
+  // when supports_multiple_windows is disabled, return true so
+  // RenderFrameHostImpl::CreateNewWindow returns with kReuse.
+  // Otherwise, return false.
+  content::WebContents* web_contents =
+      content::WebContents::FromRenderFrameHost(opener);
+  if (web_contents) {
+    CastWebPreferences* cast_prefs =
+        static_cast<CastWebPreferences*>(web_contents->GetUserData(
+            CastWebPreferences::kCastWebPreferencesDataKey));
+
+    return (cast_prefs &&
+            !cast_prefs->preferences()->supports_multiple_windows.value());
+  }
+
   return false;
 }
 

chromecast/browser/cast_web_preferences.cc

@@ -22,6 +22,10 @@ void CastWebPreferences::Update(blink::web_pref::WebPreferences* prefs) {
 
   if (preferences_.javascript_enabled)
     prefs->javascript_enabled = preferences_.javascript_enabled.value();
+
+  if (preferences_.supports_multiple_windows) {
+    prefs->supports_multiple_windows = preferences_.supports_multiple_windows.value();
+  }
 }
 
 }  // namespace chromecast

chromecast/browser/cast_web_preferences.h

@@ -21,6 +21,7 @@ class CastWebPreferences : public base::SupportsUserData::Data {
     base::Optional<blink::mojom::AutoplayPolicy> autoplay_policy;
     base::Optional<bool> hide_scrollbars;
     base::Optional<bool> javascript_enabled;
+    base::Optional<bool> supports_multiple_windows;
   };
 
   // Unique key used to identify CastWebPreferences in WebContents' user data.

chromecast/browser/webview/webview_controller.cc

@@ -69,10 +69,15 @@ WebviewController::WebviewController(content::BrowserContext* browser_context,
   contents_->SetUserData(CastWebPreferences::kCastWebPreferencesDataKey,
                          std::make_unique<CastWebPreferences>());
 
+  CastWebPreferences* cast_prefs = GetCastPreferencesFor(contents_.get());
+
   // Allow Webviews to show scrollbars. These are globally disabled since Cast
   // Apps are not expected to be scrollable.
-  GetCastPreferencesFor(contents_.get())->preferences()->hide_scrollbars =
-      false;
+  cast_prefs->preferences()->hide_scrollbars = false;
+
+  // Disallow Webviews to use multiple windows to show the new page in the
+  // existing view.
+  cast_prefs->preferences()->supports_multiple_windows = false;
 
   CastWebContents::InitParams cast_contents_init;
   cast_contents_init.is_root_window = true;