Null check BadgeManager before attempting to add it to a ReceiverSet.

In incognito and guest profiles, the BadgeManagerFactory does not create
a BadgeManager. As there are no apps in incognito/guest profiles this
would not normally be a problem. However, in BadgeManager::BindRequest,
we were attempting to add the null BadgeManager to a mojo reciever set,
causing a crash.

Note: This does not affect the API exposed to the, so this cannot be
used to detect incognito mode.

Bug: 1004122
Change-Id: I5024665257a67aaaf28aa7f3bb8cd9cfcdef2d25
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1824041Reviewed-by: Alan Cutter <alancutter@chromium.org>
Commit-Queue: Jay Harris <harrisjay@chromium.org>
Cr-Commit-Position: refs/heads/master@{#700073}

chrome/browser/badging/badge_manager.cc

@@ -52,10 +52,13 @@ void BadgeManager::BindReceiver(
     mojo::PendingReceiver<blink::mojom::BadgeService> receiver) {
   Profile* profile = Profile::FromBrowserContext(
       content::WebContents::FromRenderFrameHost(frame)->GetBrowserContext());
+
   badging::BadgeManager* badge_manager =
       badging::BadgeManagerFactory::GetInstance()->GetForProfile(profile);
-  BindingContext context(frame->GetProcess()->GetID(), frame->GetRoutingID());
+  if (!badge_manager)
+    return;
 
+  BindingContext context(frame->GetProcess()->GetID(), frame->GetRoutingID());
   badge_manager->receivers_.Add(badge_manager, std::move(receiver),
                                 std::move(context));
 }

chrome/browser/badging/badge_manager_factory.h

@@ -22,6 +22,8 @@ class BadgeManager;
 // Singleton that provides access to Profile specific BadgeManagers.
 class BadgeManagerFactory : public BrowserContextKeyedServiceFactory {
  public:
+  // Gets the BadgeManager for the current profile. |nullptr| for guest and
+  // incognito profiles.
   static BadgeManager* GetForProfile(Profile* profile);
 
   // Returns the BadgeManagerFactory singleton.

chrome/browser/ui/web_applications/web_app_badging_browsertest.cc

@@ -215,6 +215,21 @@ IN_PROC_BROWSER_TEST_P(WebAppBadgingBrowserTest,
   ASSERT_EQ(base::nullopt, last_badge_content_);
 }
 
+// Tests that badging incognito windows does not cause a crash.
+IN_PROC_BROWSER_TEST_P(WebAppBadgingBrowserTest,
+                       BadgingIncognitoWindowsDoesNotCrash) {
+  Browser* incognito_browser =
+      OpenURLOffTheRecord(profile(), main_frame_->GetLastCommittedURL());
+  RenderFrameHost* incognito_frame = incognito_browser->tab_strip_model()
+                                         ->GetActiveWebContents()
+                                         ->GetMainFrame();
+
+  ASSERT_TRUE(
+      content::ExecuteScript(incognito_frame, "ExperimentalBadge.set()"));
+  ASSERT_TRUE(
+      content::ExecuteScript(incognito_frame, "ExperimentalBadge.clear()"));
+}
+
 INSTANTIATE_TEST_SUITE_P(
     /* no prefix */,
     WebAppBadgingBrowserTest,