[iOS][coordinator] Modernize Activity Overlay Coordinator.

This CL modernizes the ActivityOverlayCoordinator to use the superclass
-initWithBaseViewController:browser:  initializer.

Also this CL updates unit tests for Activity Overlay Coordinator.

Bug: 1029346
Change-Id: I3e16373e7096355c7be9b1a7b1df53f1de4cb0c0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2019030
Commit-Queue: Nazerke Kalidolda <nazerke@google.com>
Auto-Submit: Nazerke Kalidolda <nazerke@google.com>
Reviewed-by: Mark Cogan <marq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#736921}

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

@@ -4190,8 +4190,9 @@ NSString* const kBrowserViewControllerSnackbarCategory =
     [self.activityOverlayCoordinator stop];
     self.activityOverlayCoordinator = nil;
   } else if (!self.activityOverlayCoordinator) {
-    self.activityOverlayCoordinator =
-        [[ActivityOverlayCoordinator alloc] initWithBaseViewController:self];
+    self.activityOverlayCoordinator = [[ActivityOverlayCoordinator alloc]
+        initWithBaseViewController:self
+                           browser:self.browser];
     [self.activityOverlayCoordinator start];
   }
 }

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

@@ -63,6 +63,7 @@ source_set("unit_tests") {
     ":selector_coordinator",
     "//base",
     "//base/test:test_support",
+    "//ios/chrome/browser/main:test_support",
     "//ios/chrome/test:test_support",
     "//testing/gtest",
     "//third_party/ocmock",

ios/chrome/browser/ui/elements/activity_overlay_coordinator.h

@@ -10,6 +10,15 @@
 // Coordinator for displaying an activity indicator overlay over the current
 // context.
 @interface ActivityOverlayCoordinator : ChromeCoordinator
+
+// Unavailable, use -initWithBaseViewController:browser:.
+- (instancetype)initWithBaseViewController:(UIViewController*)viewController
+    NS_UNAVAILABLE;
+// Unavailable, use -initWithBaseViewController:browser:.
+- (instancetype)initWithBaseViewController:(UIViewController*)viewController
+                              browserState:(ChromeBrowserState*)browserState
+    NS_UNAVAILABLE;
+
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_ELEMENTS_ACTIVITY_OVERLAY_COORDINATOR_H_

ios/chrome/browser/ui/elements/activity_overlay_coordinator_unittest.mm

@@ -4,6 +4,8 @@
 
 #import "ios/chrome/browser/ui/elements/activity_overlay_coordinator.h"
 
+#include "base/test/task_environment.h"
+#include "ios/chrome/browser/main/test_browser.h"
 #import "ios/chrome/browser/ui/elements/activity_overlay_view_controller.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #import "testing/gtest_mac.h"
@@ -18,12 +20,15 @@ using ActivityOverlayCoordinatorTest = PlatformTest;
 // Tests that invoking start and stop on the coordinator presents and dismisses
 // the activity overlay view, respectively.
 TEST_F(ActivityOverlayCoordinatorTest, StartAndStop) {
+  base::test::TaskEnvironment task_environment_;
   __weak UIView* overlay_view;
   @autoreleasepool {
     UIViewController* base_view_controller = [[UIViewController alloc] init];
+    std::unique_ptr<Browser> browser_ = std::make_unique<TestBrowser>();
     ActivityOverlayCoordinator* coordinator =
         [[ActivityOverlayCoordinator alloc]
-            initWithBaseViewController:base_view_controller];
+            initWithBaseViewController:base_view_controller
+                               browser:browser_.get()];
 
     EXPECT_EQ(0u, [base_view_controller.childViewControllers count]);