[ios] Add a TabStrip CollectionViewController.

This CL adds a view controller for the TabStrip and adds it as a
property to TabStripCoordinator along with other its required
properties.

Bug: 1128249,1130401, 1130400
Change-Id: I891ee1f2d5551aba7ce39c7fa68d8dfe0c56ac3e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2421108Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Nazerke Kalidolda <nazerke@google.com>
Cr-Commit-Position: refs/heads/master@{#811046}

ios/chrome/browser/ui/tab_strip/BUILD.gn

@@ -10,7 +10,23 @@ source_set("tab_strip") {
   ]
   deps = [
     "//base",
+    "//ios/chrome/browser/browser_state",
+    "//ios/chrome/browser/main:public",
     "//ios/chrome/browser/ui/coordinators:chrome_coordinators",
+    "//ios/chrome/browser/ui/tab_strip:tab_strip_ui",
+  ]
+  frameworks = [ "UIKit.framework" ]
+}
+
+source_set("tab_strip_ui") {
+  configs += [ "//build/config/compiler:enable_arc" ]
+  sources = [
+    "tab_strip_view_controller.h",
+    "tab_strip_view_controller.mm",
+  ]
+  deps = [
+    "//ios/chrome/browser/browser_state",
+    "//ios/chrome/browser/main:public",
   ]
   frameworks = [ "UIKit.framework" ]
 }

ios/chrome/browser/ui/tab_strip/tab_strip_coordinator.h

@@ -8,6 +8,8 @@
 #import "ios/chrome/browser/ui/coordinators/chrome_coordinator.h"
 
 class Browser;
+@protocol PopupMenuLongPressDelegate;
+@class TabStripViewController;
 
 // Coordinator for the tab strip.
 @interface TabStripCoordinator : ChromeCoordinator
@@ -19,6 +21,12 @@ class Browser;
 - (instancetype)initWithBaseViewController:(UIViewController*)viewController
                                    browser:(Browser*)browser NS_UNAVAILABLE;
 
+// The TabStrip view controller owned by this coordinator.
+@property(nonatomic, strong) UIViewController* viewController;
+
+// Delegate for the long press gesture recognizer triggering popup menu.
+@property(nonatomic, weak) id<PopupMenuLongPressDelegate> longPressDelegate;
+
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_TAB_STRIP_TAB_STRIP_COORDINATOR_H_

ios/chrome/browser/ui/tab_strip/tab_strip_coordinator.mm

@@ -5,14 +5,14 @@
 #import "ios/chrome/browser/ui/tab_strip/tab_strip_coordinator.h"
 
 #include "base/check_op.h"
+#import "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#import "ios/chrome/browser/main/browser.h"
+#import "ios/chrome/browser/ui/tab_strip/tab_strip_view_controller.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
-@interface TabStripCoordinator ()
-@end
-
 @implementation TabStripCoordinator
 
 #pragma mark - ChromeCoordinator
@@ -22,4 +22,27 @@
   return [super initWithBaseViewController:nil browser:browser];
 }
 
+- (void)start {
+  if (self.viewController)
+    return;
+
+  self.viewController = [[TabStripViewController alloc] init];
+  if (@available(iOS 13, *)) {
+    self.viewController.overrideUserInterfaceStyle =
+        self.browser->GetBrowserState()->IsOffTheRecord()
+            ? UIUserInterfaceStyleDark
+            : UIUserInterfaceStyleUnspecified;
+  }
+}
+
+- (void)stop {
+  self.viewController = nil;
+}
+
+#pragma mark - Properties
+
+- (void)setLongPressDelegate:(id<PopupMenuLongPressDelegate>)longPressDelegate {
+  _longPressDelegate = longPressDelegate;
+}
+
 @end

ios/chrome/browser/ui/tab_strip/tab_strip_view_controller.h

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_CHROME_BROWSER_UI_TAB_STRIP_TAB_STRIP_VIEW_CONTROLLER_H_
+#define IOS_CHROME_BROWSER_UI_TAB_STRIP_TAB_STRIP_VIEW_CONTROLLER_H_
+
+#import <UIKit/UIKit.h>
+
+@protocol PopupMenuLongPressDelegate;
+
+// ViewController for the TabStrip. This ViewController is contained by
+// BrowserViewController. This TabStripViewController is responsible for
+// responding to the different updates in the tabstrip view.
+@interface TabStripViewController : UICollectionViewController
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_TAB_STRIP_TAB_STRIP_VIEW_CONTROLLER_H_

ios/chrome/browser/ui/tab_strip/tab_strip_view_controller.mm

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "ios/chrome/browser/ui/tab_strip/tab_strip_view_controller.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+@implementation TabStripViewController
+
+@end