Remove usage of FOR_EACH_OBSERVER macro in blimp

blimp/engine/app/ui/blimp_screen.cc

 // Copyright 2015 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 "blimp/engine/app/ui/blimp_screen.h"
 
 #include "ui/aura/window.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/display/display_observer.h"
 #include "ui/gfx/geometry/size.h"
@@ skipping 21 matching lines @@
 
   uint32_t metrics = display::DisplayObserver::DISPLAY_METRIC_NONE;
   if (scale != display_.device_scale_factor())
     metrics |= display::DisplayObserver::DISPLAY_METRIC_DEVICE_SCALE_FACTOR;
 
   if (size != display_.GetSizeInPixel())
     metrics |= display::DisplayObserver::DISPLAY_METRIC_BOUNDS;
 
   display_.SetScaleAndBounds(scale, gfx::Rect(size));
 
-  FOR_EACH_OBSERVER(display::DisplayObserver, observers_,
-                    OnDisplayMetricsChanged(display_, metrics));
+  for (auto& observer : observers_)
+    observer.OnDisplayMetricsChanged(display_, metrics);
 }
 
 gfx::Point BlimpScreen::GetCursorScreenPoint() {
   return gfx::Point();
 }
 
 bool BlimpScreen::IsWindowUnderCursor(gfx::NativeWindow window) {
   NOTIMPLEMENTED();
   return false;
 }
@@ skipping 34 matching lines @@
 void BlimpScreen::AddObserver(display::DisplayObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void BlimpScreen::RemoveObserver(display::DisplayObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 }  // namespace engine
 }  // namespace blimp