[Mac] Test for BrowserTouchBar's BookmarkTabHelperObserver

Add a test that checks if the BrowserTouchBar's
BookmarkTapHelperObserver gets removed when it's destroyed.

Follow up to:
https://chromium-review.googlesource.com/c/chromium/src/+/1099483

Bug: 852222
Change-Id: I60c08a195a8b8adb1848d120c3492783fa615ba9
Reviewed-on: https://chromium-review.googlesource.com/1101484
Commit-Queue: Sarah Chan <spqchan@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568206}

chrome/browser/ui/bookmarks/bookmark_tab_helper.cc

@@ -80,6 +80,10 @@ void BookmarkTabHelper::RemoveObserver(BookmarkTabHelperObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
+bool BookmarkTabHelper::HasObserver(BookmarkTabHelperObserver* observer) const {
+  return observers_.HasObserver(observer);
+}
+
 BookmarkTabHelper::BookmarkTabHelper(content::WebContents* web_contents)
     : content::WebContentsObserver(web_contents),
       is_starred_(false),

chrome/browser/ui/bookmarks/bookmark_tab_helper.h

@@ -56,6 +56,7 @@ class BookmarkTabHelper
 
   void AddObserver(BookmarkTabHelperObserver* observer);
   void RemoveObserver(BookmarkTabHelperObserver* observer);
+  bool HasObserver(BookmarkTabHelperObserver* observer) const;
 
  private:
   friend class content::WebContentsUserData<BookmarkTabHelper>;

chrome/browser/ui/cocoa/browser_window_controller.mm

@@ -1874,7 +1874,7 @@ willAnimateFromState:(BookmarkBar::State)oldState
 }
 
 - (void)setBrowserWindowTouchBar:(BrowserWindowTouchBar*)touchBar {
-  touchBar_.reset(touchBar);
+  touchBar_.reset([touchBar retain]);
 }
 
 - (void)executeExtensionCommand:(const std::string&)extension_id

chrome/browser/ui/cocoa/browser_window_touch_bar.h

@@ -10,6 +10,7 @@
 #include "base/mac/availability.h"
 #import "ui/base/cocoa/touch_bar_forward_declarations.h"
 
+class BookmarkTabHelperObserver;
 class Browser;
 @class BrowserWindowController;
 
@@ -53,6 +54,10 @@ class Browser;
 // it's null.
 - (NSSegmentedControl*)backForwardControl;
 
+// Returns the bridge object that BrowserWindowTouchBar uses to receive
+// notifications.
+- (BookmarkTabHelperObserver*)bookmarkTabObserver;
+
 @end
 
 #endif  // CHROME_BROWSER_UI_COCOA_BROWSER_WINDOW_TOUCH_BAR_H_

chrome/browser/ui/cocoa/browser_window_touch_bar.mm

@@ -616,4 +616,8 @@ class BrowserTouchBarNotificationBridge : public CommandObserver,
   return backForwardControl_.get();
 }
 
+- (BookmarkTabHelperObserver*)bookmarkTabObserver {
+  return notificationBridge_.get();
+}
+
 @end

chrome/browser/ui/cocoa/browser_window_touch_bar_browsertest.mm

@@ -3,6 +3,8 @@
 // found in the LICENSE file.
 
 #include "chrome/app/chrome_command_ids.h"
+#include "chrome/browser/ui/bookmarks/bookmark_tab_helper.h"
+#include "chrome/browser/ui/bookmarks/bookmark_tab_helper_observer.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_window.h"
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
@@ -27,19 +29,23 @@ class BrowserWindowTouchBarTest : public InProcessBrowserTest {
   BrowserWindowTouchBarTest() : InProcessBrowserTest() {}
 
   void SetUpOnMainThread() override {
-    // Ownership is passed to BrowserWindowController in
-    // -setBrowserWindowTouchBar:
-    browser_touch_bar_ = [[BrowserWindowTouchBar alloc]
+    browser_touch_bar_.reset([[BrowserWindowTouchBar alloc]
         initWithBrowser:browser()
-                 window:[browser_window_controller() window]];
-    [browser_window_controller() setBrowserWindowTouchBar:browser_touch_bar_];
+                 window:[browser_window_controller() window]]);
+    [browser_window_controller()
+        setBrowserWindowTouchBar:browser_touch_bar_.get()];
   }
 
   void TearDownOnMainThread() override {
-    [browser_window_controller() setBrowserWindowTouchBar:nil];
+    DestroyBrowserWindowTouchBar();
     InProcessBrowserTest::TearDownOnMainThread();
   }
 
+  void DestroyBrowserWindowTouchBar() {
+    [browser_window_controller() setBrowserWindowTouchBar:nil];
+    browser_touch_bar_.reset();
+  }
+
   BrowserWindowController* browser_window_controller() {
     return [BrowserWindowController
         browserWindowControllerForWindow:browser()
@@ -52,7 +58,7 @@ class BrowserWindowTouchBarTest : public InProcessBrowserTest {
   }
 
  private:
-  BrowserWindowTouchBar* browser_touch_bar_;
+  base::scoped_nsobject<BrowserWindowTouchBar> browser_touch_bar_;
 
   test::ScopedMacViewsBrowserMode cocoa_browser_mode_{false};
 
@@ -99,3 +105,24 @@ IN_PROC_BROWSER_TEST_F(BrowserWindowTouchBarTest, SearchEngineChanges) {
     EXPECT_NE(touch_bar, [window touchBar]);
   }
 }
+
+// Tests to see if the touch bar's bookmark tab helper observer gets removed
+// when the touch bar is destroyed.
+IN_PROC_BROWSER_TEST_F(BrowserWindowTouchBarTest, DestroyNotificationBridge) {
+  if (@available(macOS 10.12.2, *)) {
+    BookmarkTabHelperObserver* observer =
+        [browser_touch_bar() bookmarkTabObserver];
+    std::unique_ptr<content::WebContents> contents =
+        content::WebContents::Create(
+            content::WebContents::CreateParams(browser()->profile()));
+    browser()->tab_strip_model()->AppendWebContents(std::move(contents), true);
+
+    BookmarkTabHelper* tab_helper = BookmarkTabHelper::FromWebContents(
+        browser()->tab_strip_model()->GetActiveWebContents());
+    DCHECK(tab_helper);
+    EXPECT_TRUE(tab_helper->HasObserver(observer));
+
+    DestroyBrowserWindowTouchBar();
+    EXPECT_FALSE(tab_helper->HasObserver(observer));
+  }
+}