Remove FOR_EACH_OBSERVER from arc/ since it's being deprecated

components/arc/test/fake_arc_bridge_bootstrap.cc

 // 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.
 
 #include "components/arc/test/fake_arc_bridge_bootstrap.h"
 
 #include <memory>
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 
 namespace arc {
 
 FakeArcBridgeBootstrap::FakeArcBridgeBootstrap() = default;
 
 FakeArcBridgeBootstrap::~FakeArcBridgeBootstrap() = default;
 
 void FakeArcBridgeBootstrap::Start() {
   if (boot_failure_emulation_enabled_) {
-    FOR_EACH_OBSERVER(Observer, observer_list_,
-                      OnStopped(boot_failure_reason_));
+    for (auto& observer : observer_list_)
+      observer.OnStopped(boot_failure_reason_);
   } else if (!boot_suspended_) {
-    FOR_EACH_OBSERVER(Observer, observer_list_, OnReady());
+    for (auto& observer : observer_list_)
+      observer.OnReady();
   }
 }
 
 void FakeArcBridgeBootstrap::Stop() {
   StopWithReason(ArcBridgeService::StopReason::SHUTDOWN);
 }
 
 void FakeArcBridgeBootstrap::StopWithReason(
     ArcBridgeService::StopReason reason) {
-  FOR_EACH_OBSERVER(Observer, observer_list_, OnStopped(reason));
+  for (auto& observer : observer_list_)
+    observer.OnStopped(reason);
 }
 
 void FakeArcBridgeBootstrap::EnableBootFailureEmulation(
     ArcBridgeService::StopReason reason) {
   DCHECK(!boot_failure_emulation_enabled_);
   DCHECK(!boot_suspended_);
 
   boot_failure_emulation_enabled_ = true;
   boot_failure_reason_ = reason;
 }
 
 void FakeArcBridgeBootstrap::SuspendBoot() {
   DCHECK(!boot_failure_emulation_enabled_);
   DCHECK(!boot_suspended_);
 
   boot_suspended_ = true;
 }
 
 // static
 std::unique_ptr<ArcBridgeBootstrap> FakeArcBridgeBootstrap::Create() {
   return base::MakeUnique<FakeArcBridgeBootstrap>();
 }
 
 }  // namespace arc