[iOS] Fix shutdown crash in BVC.

Plumbs dispatcher to BVC. Makes the browser coordinator zero it out
during shutdown before stopping child coordinators to avoid a crash.

Bug: 1137686
Test: No repro steps available.
Change-Id: Ica001018459d3667c53f010487292ffae774d8ee
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2471737Reviewed-by: Mark Cogan <marq@chromium.org>
Commit-Queue: Stepan Khapugin <stkhapugin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#817453}

ios/chrome/browser/test/perf_test_with_bvc_ios.mm

@@ -123,7 +123,8 @@ void PerfTestWithBVC::SetUp() {
                      initWithBrowser:browser_.get()
                    dependencyFactory:bvc_factory_
       browserContainerViewController:[[BrowserContainerViewController alloc]
-                                         init]];
+                                         init]
+                          dispatcher:browser_->GetCommandDispatcher()];
   [bvc_ setActive:YES];
 
   // Create a real window to give to the browser view controller.

ios/chrome/browser/ui/browser_view/browser_coordinator.mm

@@ -242,6 +242,7 @@
   [self removeWebStateListObserver];
   [self uninstallDelegatesForBrowser];
   [self uninstallDelegatesForAllWebStates];
+  self.viewController.commandDispatcher = nil;
   [self.dispatcher stopDispatchingToTarget:self];
   [self stopChildCoordinators];
   [self destroyViewController];
@@ -305,7 +306,8 @@
                      initWithBrowser:self.browser
                    dependencyFactory:factory
       browserContainerViewController:self.browserContainerCoordinator
-                                         .viewController];
+                                         .viewController
+                          dispatcher:self.dispatcher];
 }
 
 // Shuts down the BrowserViewController.

ios/chrome/browser/ui/browser_view/browser_view_controller.h

@@ -20,6 +20,7 @@
 class Browser;
 @class BrowserContainerViewController;
 @class BrowserViewControllerDependencyFactory;
+@class CommandDispatcher;
 @class ToolbarAccessoryPresenter;
 
 // The top-level view controller for the browser UI. Manages other controllers
@@ -42,6 +43,7 @@ class Browser;
                      (BrowserViewControllerDependencyFactory*)factory
     browserContainerViewController:
         (BrowserContainerViewController*)browserContainerViewController
+                        dispatcher:(CommandDispatcher*)dispatcher
     NS_DESIGNATED_INITIALIZER;
 
 - (instancetype)initWithNibName:(NSString*)nibNameOrNil
@@ -49,6 +51,9 @@ class Browser;
 
 - (instancetype)initWithCoder:(NSCoder*)aDecoder NS_UNAVAILABLE;
 
+// Command dispatcher.
+@property(nonatomic, weak) CommandDispatcher* commandDispatcher;
+
 // Returns whether or not text to speech is playing.
 @property(nonatomic, assign, readonly, getter=isPlayingTTS) BOOL playingTTS;
 

ios/chrome/browser/ui/browser_view/browser_view_controller.mm

@@ -480,8 +480,6 @@ NSString* const kBrowserViewControllerSnackbarCategory =
     BrowserContainerViewController* browserContainerViewController;
 // Invisible button used to dismiss the keyboard.
 @property(nonatomic, strong) UIButton* typingShield;
-// Command dispatcher.
-@property(nonatomic, weak) CommandDispatcher* commandDispatcher;
 // The browser's side swipe controller.  Lazily instantiated on the first call.
 @property(nonatomic, strong, readonly) SideSwipeController* sideSwipeController;
 // The object that manages keyboard commands on behalf of the BVC.
@@ -717,14 +715,15 @@ NSString* const kBrowserViewControllerSnackbarCategory =
                  dependencyFactory:
                      (BrowserViewControllerDependencyFactory*)factory
     browserContainerViewController:
-        (BrowserContainerViewController*)browserContainerViewController {
+        (BrowserContainerViewController*)browserContainerViewController
+                        dispatcher:(CommandDispatcher*)dispatcher {
   self = [super initWithNibName:nil bundle:base::mac::FrameworkBundle()];
   if (self) {
     DCHECK(factory);
 
+    _commandDispatcher = dispatcher;
     _browserContainerViewController = browserContainerViewController;
     _dependencyFactory = factory;
-    self.commandDispatcher = browser->GetCommandDispatcher();
     self.textZoomHandler =
         HandlerForProtocol(self.commandDispatcher, TextZoomCommands);
     [self.commandDispatcher

ios/chrome/browser/ui/browser_view/browser_view_controller_unittest.mm

@@ -164,9 +164,11 @@ class BrowserViewControllerTest : public BlockCleanupTest {
         std::make_unique<FakeClipboardRecentContent>());
 
     container_ = [[BrowserContainerViewController alloc] init];
-    bvc_ = [[BrowserViewController alloc] initWithBrowser:browser_.get()
-                                        dependencyFactory:factory
-                           browserContainerViewController:container_];
+    bvc_ = [[BrowserViewController alloc]
+                       initWithBrowser:browser_.get()
+                     dependencyFactory:factory
+        browserContainerViewController:container_
+                            dispatcher:browser_->GetCommandDispatcher()];
 
     // Force the view to load.
     UIWindow* window = [[UIWindow alloc] initWithFrame:CGRectZero];