Check that tab switcher is active/inactive before visibility check.

As shown in the referenced bug, testCloseAllTabs was failing because the
stack view visibility check was checking for a nil stack view.  This is
likely occurring because the visibility check was occurring before the
touch event that should show the tab switcher is handled.  Adding this
condition will wait for the touch event to be handled before checking
for visibility.

BUG=693517

Review-Url: https://codereview.chromium.org/2706403006
Cr-Commit-Position: refs/heads/master@{#455293}
(cherry picked from commit 389418d)

Review-Url: https://codereview.chromium.org/2734283002 .
Cr-Commit-Position: refs/branch-heads/3029@{#56}
Cr-Branched-From: 939b32e-refs/heads/master@{#454471}

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

@@ -144,6 +144,7 @@ source_set("eg_tests") {
     "//ios/chrome/browser/ui/tools_menu",
     "//ios/chrome/test/app:test_support",
     "//ios/chrome/test/earl_grey:test_support",
+    "//ios/testing:ios_test_support",
     "//ios/testing/earl_grey:earl_grey_support",
   ]
   libs = [ "XCTest.framework" ]

ios/chrome/browser/ui/stack_view/stack_view_egtest.mm

@@ -24,6 +24,7 @@
 #import "ios/chrome/test/earl_grey/chrome_matchers.h"
 #import "ios/chrome/test/earl_grey/chrome_test_case.h"
 #include "ios/testing/earl_grey/disabled_test_macros.h"
+#import "ios/testing/wait_util.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
@@ -50,7 +51,30 @@
   return ViewMatchingView([chrome_test_util::GetStackViewController() view]);
 }
 
-// Waits for the Stack View to be visible/hidden.
+// Waits for the Stack View to be active/inactive.
+void WaitForStackViewActive(bool active) {
+  NSString* activeStatusString = active ? @"active" : @"inactive";
+  NSString* activeTabSwitcherDescription =
+      [NSString stringWithFormat:@"Waiting for tab switcher to be %@.",
+                                 activeStatusString];
+  BOOL (^activeTabSwitcherBlock)
+  () = ^BOOL {
+    BOOL isActive = chrome_test_util::GetStackViewController() &&
+                    chrome_test_util::IsTabSwitcherActive();
+    return active ? isActive : !isActive;
+  };
+  GREYCondition* activeTabSwitcherCondition =
+      [GREYCondition conditionWithName:activeTabSwitcherDescription
+                                 block:activeTabSwitcherBlock];
+  NSString* assertDescription = [NSString
+      stringWithFormat:@"Tab switcher did not become %@.", activeStatusString];
+
+  GREYAssert([activeTabSwitcherCondition
+                 waitWithTimeout:testing::kWaitForUIElementTimeout],
+             assertDescription);
+}
+
+// Verify the visibility of the stack view.
 void CheckForStackViewVisibility(bool visible) {
   id<GREYMatcher> visibilityMatcher =
       grey_allOf(visible ? grey_sufficientlyVisible() : grey_notVisible(),
@@ -70,6 +94,7 @@ void OpenStackView() {
   [[EarlGrey selectElementWithMatcher:stackButtonMatcher]
       performAction:grey_tap()];
   // Verify that a StackViewController was presented.
+  WaitForStackViewActive(true);
   CheckForStackViewVisibility(true);
 }
 
@@ -105,6 +130,7 @@ void OpenNewTabUsingStackView() {
   ShowDeckWithType(DeckType::NORMAL);
   [[EarlGrey selectElementWithMatcher:grey_accessibilityID(@"New Tab")]
       performAction:grey_tap()];
+  WaitForStackViewActive(false);
   CheckForStackViewVisibility(false);
 }
 
@@ -121,6 +147,7 @@ void OpenNewIncognitoTabUsingStackView() {
   NSString* newIncognitoTabID = kToolsMenuNewIncognitoTabId;
   [[EarlGrey selectElementWithMatcher:grey_accessibilityID(newIncognitoTabID)]
       performAction:grey_tap()];
+  WaitForStackViewActive(false);
   CheckForStackViewVisibility(false);
 }
 
@@ -137,6 +164,7 @@ void SelectTabUsingStackView(Tab* tab) {
   [[EarlGrey selectElementWithMatcher:ViewMatchingView(card_title_label)]
       performAction:grey_tap()];
   // Wait for the StackViewController to be dismissed.
+  WaitForStackViewActive(false);
   CheckForStackViewVisibility(false);
   // Checks that the next Tab has been selected.
   GREYAssertEqual(tab, chrome_test_util::GetCurrentTab(),
@@ -187,13 +215,7 @@ - (void)testCloseTab {
 }
 
 // Tests closing all Tabs in the stack view.
-// TODO(crbug.com/693517): Re-enable this test on simulator.
-#if TARGET_IPHONE_SIMULATOR
-#define MAYBE_testCloseAllTabs FLAKY_testCloseAllTabs
-#else
-#define MAYBE_testCloseAllTabs testCloseAllTabs
-#endif
-- (void)MAYBE_testCloseAllTabs {
+- (void)testCloseAllTabs {
   // The StackViewController is only used on iPhones.
   if (IsIPadIdiom())
     EARL_GREY_TEST_SKIPPED(@"Stack view is not used on iPads.");