Remove calls to MessageLoop::Run/RunUntilIdle from ios/.

ios/chrome/app/application_delegate/memory_warning_helper_unittest.mm

 // Copyright 2016 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/app/application_delegate/memory_warning_helper.h"
 
 #include "base/mac/bind_objc_block.h"
 #import "base/mac/scoped_nsobject.h"
 #include "base/memory/memory_pressure_listener.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "base/threading/thread.h"
 #import "ios/chrome/browser/metrics/previous_session_info.h"
 #include "testing/platform_test.h"
 
 using previous_session_info_constants::
     kDidSeeMemoryWarningShortlyBeforeTerminating;
 
 class MemoryWarningHelperTest : public PlatformTest {
  protected:
   MemoryWarningHelperTest() {
@@ skipping 14 matching lines @@
     if (!memory_helper_) {
       memory_helper_.reset([[MemoryWarningHelper alloc] init]);
     }
     return memory_helper_;
   }
 
   // Callback for |memory_pressure_listener_|.
   void OnMemoryPressure(
       base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level) {
     memory_pressure_level_ = memory_pressure_level;
-    message_loop_.QuitWhenIdle();
+    run_loop_.QuitWhenIdle();
   }
 
-  base::MessageLoop& message_loop() { return message_loop_; }
+  void RunMessageLoop() { run_loop_.Run(); }
 
  private:
   base::MessageLoop message_loop_;
+  base::RunLoop run_loop_;
   base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level_;
   std::unique_ptr<base::MemoryPressureListener> memory_pressure_listener_;
   base::scoped_nsobject<MemoryWarningHelper> memory_helper_;
 
   DISALLOW_COPY_AND_ASSIGN(MemoryWarningHelperTest);
 };
 
 // Invokes resetForegroundMemoryWarningCount and verifies the
 // foregroundMemoryWarningCount is setted to 0.
 TEST_F(MemoryWarningHelperTest, VerifyForegroundMemoryWarningCountReset) {
   // Setup.
   [GetMemoryHelper() handleMemoryPressure];
   ASSERT_TRUE(GetMemoryHelper().foregroundMemoryWarningCount != 0);
 
   // Action.
   [GetMemoryHelper() resetForegroundMemoryWarningCount];
 
   // Test.
   EXPECT_EQ(0, GetMemoryHelper().foregroundMemoryWarningCount);
 }
 
 // Invokes applicationDidReceiveMemoryWarning and verifies the memory pressure
 // callback (i.e. MainControllerTest::OnMemoryPressure) is invoked.
 TEST_F(MemoryWarningHelperTest, VerifyApplicationDidReceiveMemoryWarning) {
   [GetMemoryHelper() handleMemoryPressure];
-  message_loop().Run();
+  RunMessageLoop();
   EXPECT_EQ(base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL,
             GetMemoryPressureLevel());
 }
 
 // Invokes applicationDidReceiveMemoryWarning and verifies the flags (i.e.
 // breakpad_helper and NSUserDefaults) are set.
 TEST_F(MemoryWarningHelperTest, VerifyHelperDidSetMemoryWarningFlags) {
   // Setup.
   [[PreviousSessionInfo sharedInstance] beginRecordingCurrentSession];
   [[PreviousSessionInfo sharedInstance] resetMemoryWarningFlag];
   int foregroundMemoryWarningCountBeforeWarning =
       GetMemoryHelper().foregroundMemoryWarningCount;
 
   BOOL memoryWarningFlagBeforeAlert = [[NSUserDefaults standardUserDefaults]
       boolForKey:kDidSeeMemoryWarningShortlyBeforeTerminating];
 
   // Action.
   [GetMemoryHelper() handleMemoryPressure];
 
   // Tests.
   EXPECT_TRUE([[NSUserDefaults standardUserDefaults]
       boolForKey:kDidSeeMemoryWarningShortlyBeforeTerminating]);
   EXPECT_FALSE(memoryWarningFlagBeforeAlert);
   EXPECT_EQ(foregroundMemoryWarningCountBeforeWarning + 1,
             GetMemoryHelper().foregroundMemoryWarningCount);
 }