Revert "[ios] Adds the ability to run unittests using XCTest."

This reverts commit b6c231b5.

Reason for revert: Suspected for causing compiling errors on mac.

Original change's description:
> [ios] Adds the ability to run unittests using XCTest.
> 
> This new functionality is hidden behind both a GN arg
> (enable_run_ios_unittests_with_xctest) and a commandline switch
> (--enable-run-unittests-with-xctest), in order to default it to off
> until the bots are updated to properly run XCTest-based unittests.
> 
> The iOS test runner is updated to run in one of two modes.  When
> --enable-run-unittests-with-xctest is false (the default), behavior is
> unchanged; TestSuite::Run() calls UIApplicationMain(), then the
> UIApplicationDelegate calls TestSuite::Run() again, which actually runs
> the tests when invoked the second time.  When the switch is set to true,
> the second invocation of TestSuite::Run() is made by our XCTestCase
> subclass rather than by the application delegate.
> 
> Xcode provides the ability to run XCTests and XCUITests from the
> commandline, but does not provide any other way to install and run an
> app outside of this test-based workflow.  (We had an alternative that
> used third party libraries, but they no longer work on iOS 13.)  This
> makes it difficult to install and run GoogleTest-based tests on iOS
> devices, since they run as a single self-contained application, but it
> would not be practical to drop GoogleTest support on iOS.  Instead, we
> are exploring invoking these tests via XCTest, which would allow us to
> use Xcode's tooling but still run the same GoogleTest-based tests as on
> other platforms.
> 
> BUG=635509
> 
> Change-Id: I26c67d9c7e16a744f43a20f2d8c5839ca8b3c31a
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1787593
> Reviewed-by: Dirk Pranke <dpranke@chromium.org>
> Reviewed-by: Mark Mentovai <mark@chromium.org>
> Reviewed-by: Justin Cohen <justincohen@chromium.org>
> Commit-Queue: Rohit Rao <rohitrao@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#694749}

TBR=rohitrao@chromium.org,dpranke@chromium.org,justincohen@chromium.org,mark@chromium.org

Change-Id: Ic67605ab0292551500a163e993c6d93fec3048c0
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 635509,1002144
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1791798Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#694814}

base/test/BUILD.gn

@@ -228,7 +228,6 @@ static_library("test_support") {
     set_sources_assignment_filter([])
     sources += [ "test_file_util_mac.cc" ]
     set_sources_assignment_filter(sources_assignment_filter)
-    deps += [ ":google_test_runner_shared_headers" ]
   }
 
   if (is_mac) {
@@ -514,29 +513,6 @@ if (is_android) {
   }
 }
 
-if (is_ios) {
-  source_set("google_test_runner_shared_headers") {
-    sources = [
-      "ios/google_test_runner_delegate.h",
-    ]
-  }
-
-  source_set("google_test_runner") {
-    sources = [
-      "ios/google_test_runner.mm",
-    ]
-    deps = [
-      ":google_test_runner_shared_headers",
-      "//base",
-    ]
-    libs = [ "UIKit.framework" ]
-    configs += [
-      "//build/config/compiler:enable_arc",
-      "//build/config/ios:xctest_config",
-    ]
-  }
-}
-
 # Trivial executable which outputs space-delimited argv to stdout,
 # used for testing.
 executable("test_child_process") {

base/test/ios/google_test_runner.mm

-// Copyright 2019 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 <UIKit/UIKit.h>
-#import <XCTest/XCTest.h>
-
-#include "base/logging.h"
-#import "base/test/ios/google_test_runner_delegate.h"
-
-#if !defined(__has_feature) || !__has_feature(objc_arc)
-#error "This file requires ARC support."
-#endif
-
-@interface GoogleTestRunner : XCTestCase
-@end
-
-@implementation GoogleTestRunner
-
-- (void)testRunGoogleTests {
-  id appDelegate = UIApplication.sharedApplication.delegate;
-  DCHECK([appDelegate conformsToProtocol:@protocol(GoogleTestRunnerDelegate)]);
-
-  id<GoogleTestRunnerDelegate> runnerDelegate =
-      static_cast<id<GoogleTestRunnerDelegate>>(appDelegate);
-  DCHECK(runnerDelegate.supportsRunningGoogleTests);
-  XCTAssertTrue([runnerDelegate runGoogleTests] == 0);
-}
-
-@end

base/test/ios/google_test_runner_delegate.h

-// Copyright 2019 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 BASE_TEST_IOS_GOOGLE_TEST_RUNNER_DELEGATE_H_
-#define BASE_TEST_IOS_GOOGLE_TEST_RUNNER_DELEGATE_H_
-
-@protocol GoogleTestRunnerDelegate
-
-// Returns YES if this delegate supports running GoogleTests via a call to
-// |runGoogleTests|.
-@property(nonatomic, readonly, assign) BOOL supportsRunningGoogleTests;
-
-// Runs GoogleTests and returns the final exit code.
-- (int)runGoogleTests;
-
-@end
-
-#endif  // BASE_TEST_IOS_GOOGLE_TEST_RUNNER_DELEGATE_H_

base/test/test_support_ios.h

@@ -19,9 +19,6 @@ void InitIOSRunHook(TestSuite* suite, int argc, char* argv[]);
 // InitIOSRunHook.
 void RunTestsFromIOSApp();
 
-// Returns true if unittests should be run by the XCTest runnner.
-bool ShouldRunIOSUnittestsWithXCTest();
-
 }  // namespace base
 
 #endif  // BASE_TEST_TEST_SUPPORT_IOS_H_

base/test/test_support_ios.mm

@@ -2,19 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#import "base/test/test_support_ios.h"
-
 #import <UIKit/UIKit.h>
 
-#include "base/command_line.h"
 #include "base/debug/debugger.h"
 #include "base/logging.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/message_loop/message_pump.h"
 #include "base/message_loop/message_pump_default.h"
-#import "base/test/ios/google_test_runner_delegate.h"
 #include "base/test/test_suite.h"
-#include "base/test/test_switches.h"
 #include "testing/coverage_util_ios.h"
 
 // Springboard will kill any iOS app that fails to check in after launch within
@@ -50,7 +45,7 @@ static char** g_argv;
 @end
 #endif  // TARGET_IPHONE_SIMULATOR
 
-@interface ChromeUnitTestDelegate : NSObject <GoogleTestRunnerDelegate> {
+@interface ChromeUnitTestDelegate : NSObject {
   base::scoped_nsobject<UIWindow> _window;
 }
 - (void)runTests;
@@ -91,12 +86,9 @@ static char** g_argv;
     [self redirectOutput];
 
   // Queue up the test run.
-  if (!base::ShouldRunIOSUnittestsWithXCTest()) {
-    // When running in XCTest mode, XCTest will invoke |runGoogleTest| directly.
-    // Otherwise, schedule a call to |runTests|.
-    [self performSelector:@selector(runTests) withObject:nil afterDelay:0.1];
-  }
-
+  [self performSelector:@selector(runTests)
+             withObject:nil
+             afterDelay:0.1];
   return YES;
 }
 
@@ -158,11 +150,7 @@ static char** g_argv;
   }
 }
 
-- (BOOL)supportsRunningGoogleTests {
-  return base::ShouldRunIOSUnittestsWithXCTest();
-}
-
-- (int)runGoogleTests {
+- (void)runTests {
   coverage_util::ConfigureCoverageReportPath();
 
   int exitStatus = g_test_suite->Run();
@@ -170,14 +158,6 @@ static char** g_argv;
   if ([self shouldRedirectOutputToFile])
     [self writeOutputToNSLog];
 
-  return exitStatus;
-}
-
-- (void)runTests {
-  DCHECK(!base::ShouldRunIOSUnittestsWithXCTest());
-
-  int exitStatus = [self runGoogleTests];
-
   // If a test app is too fast, it will exit before Instruments has has a
   // a chance to initialize and no test results will be seen.
   // TODO(crbug.com/137010): Figure out how much time is actually needed, and
@@ -236,9 +216,4 @@ void RunTestsFromIOSApp() {
   }
 }
 
-bool ShouldRunIOSUnittestsWithXCTest() {
-  return base::CommandLine::ForCurrentProcess()->HasSwitch(
-      switches::kEnableRunIOSUnittestsWithXCTest);
-}
-
 }  // namespace base

base/test/test_switches.cc

@@ -84,9 +84,3 @@ const char switches::kTestLauncherTrace[] = "test-launcher-trace";
 const char switches::kTestTinyTimeout[] = "test-tiny-timeout";
 const char switches::kUiTestActionTimeout[] = "ui-test-action-timeout";
 const char switches::kUiTestActionMaxTimeout[] = "ui-test-action-max-timeout";
-
-#if defined(OS_IOS)
-// If enabled, runs unittests using the XCTest test runner.
-const char switches::kEnableRunIOSUnittestsWithXCTest[] =
-    "enable-run-ios-unittests-with-xctest";
-#endif

base/test/test_switches.h

@@ -5,8 +5,6 @@
 #ifndef BASE_TEST_TEST_SWITCHES_H_
 #define BASE_TEST_TEST_SWITCHES_H_
 
-#include "build/build_config.h"
-
 namespace switches {
 
 // All switches in alphabetical order. The switches should be documented
@@ -34,10 +32,6 @@ extern const char kTestTinyTimeout[];
 extern const char kUiTestActionTimeout[];
 extern const char kUiTestActionMaxTimeout[];
 
-#if defined(OS_IOS)
-extern const char kEnableRunIOSUnittestsWithXCTest[];
-#endif
-
 }  // namespace switches
 
 #endif  // BASE_TEST_TEST_SWITCHES_H_

build/config/ios/rules.gni

@@ -1808,20 +1808,13 @@ template("ios_xctest_test") {
   _host_target = _target_name
   _host_output = _output_name
 
-  # Allow invokers to specify their own target for the xctest module, but
-  # fall back to a default (empty) module otherwise.
-  if (defined(invoker.xctest_module_target)) {
-    _xctest_module_target = invoker.xctest_module_target
-  } else {
-    _xctest_module_target_name = _xctest_target + "shell_source"
-    _xctest_module_target = ":$_xctest_module_target_name"
-    source_set(_xctest_module_target_name) {
-      sources = [
-        "//build/config/ios/xctest_shell.mm",
-      ]
+  _xctest_shell_source_target = _xctest_target + "shell_source"
+  source_set(_xctest_shell_source_target) {
+    sources = [
+      "//build/config/ios/xctest_shell.mm",
+    ]
 
-      configs += [ "//build/config/ios:xctest_config" ]
-    }
+    configs += [ "//build/config/ios:xctest_config" ]
   }
 
   ios_xctest_bundle(_xctest_target) {
@@ -1831,7 +1824,7 @@ template("ios_xctest_test") {
     xcode_test_application_name = _host_output
 
     deps = [
-      _xctest_module_target,
+      ":$_xctest_shell_source_target",
     ]
   }
 

testing/test.gni

@@ -293,14 +293,6 @@ template("test") {
     import("//build/config/ios/ios_sdk.gni")
     import("//build/config/ios/rules.gni")
 
-    declare_args() {
-      # Keep the unittest-as-xctest functionality defaulted to off until the
-      # bots are updated to handle it properly.
-      # TODO(crbug.com/1001667): Remove this arg once the iOS test runner
-      # supports running unittests with xctest.
-      enable_run_ios_unittests_with_xctest = false
-    }
-
     _test_target = target_name
     _resources_bundle_data = target_name + "_resources_bundle_data"
 
@@ -314,19 +306,9 @@ template("test") {
       ]
     }
 
-    if (enable_run_ios_unittests_with_xctest) {
-      ios_test_target_type = "ios_xctest_test"
-    } else {
-      ios_test_target_type = "ios_app_bundle"
-    }
-
-    target(ios_test_target_type, _test_target) {
+    ios_app_bundle(_test_target) {
       testonly = true
 
-      if (enable_run_ios_unittests_with_xctest) {
-        xctest_module_target = "//base/test:google_test_runner"
-      }
-
       # See above call.
       set_sources_assignment_filter([])
       forward_variables_from(invoker, "*", [ "testonly" ])