Reland of Android: support multiple displays on C++ side

ui/display/screen.cc

 // Copyright 2012 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 "ui/display/screen.h"
 
 #include "ui/display/display.h"
 #include "ui/gfx/geometry/rect.h"
 
 namespace display {
 
 namespace {
 
 Screen* g_screen;
 
 }  // namespace
 
 Screen::Screen() {}
 
 Screen::~Screen() {}
 
 // static
 Screen* Screen::GetScreen() {
-#if defined(OS_MACOSX) || defined(OS_ANDROID)
+#if defined(OS_MACOSX)
   // TODO(scottmg): https://crbug.com/558054
   if (!g_screen)
     g_screen = CreateNativeScreen();
 #endif
   return g_screen;
 }
 
 // static
 void Screen::SetScreenInstance(Screen* instance) {
   g_screen = instance;
 }
 
 gfx::Rect Screen::ScreenToDIPRectInWindow(gfx::NativeView view,
                                           const gfx::Rect& screen_rect) const {
   float scale = GetDisplayNearestWindow(view).device_scale_factor();
   return ScaleToEnclosingRect(screen_rect, 1.0f / scale);
 }
 
 gfx::Rect Screen::DIPToScreenRectInWindow(gfx::NativeView view,
                                           const gfx::Rect& dip_rect) const {
   float scale = GetDisplayNearestWindow(view).device_scale_factor();
   return ScaleToEnclosingRect(dip_rect, scale);
 }
 
 }  // namespace display