Adds an iOS implementation of gfx::Image.

ui/base/layout.cc

 // Copyright (c) 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/base/layout.h"
 
 #include <algorithm>
 #include <cmath>
 #include <limits>
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "build/build_config.h"
 #include "ui/base/ui_base_switches.h"
 
 #if defined(USE_AURA) && !defined(OS_WIN)
 #include "ui/aura/root_window.h"
 #include "ui/compositor/compositor.h"
 #endif  // defined(USE_AURA) && !defined(OS_WIN)
 
-#if defined(OS_MACOSX)
+#if defined(OS_MACOSX) && !defined(OS_IOS)
 #include "base/mac/mac_util.h"
 #endif
 
 #if defined(OS_WIN)
 #include "base/win/metro.h"
 #include <Windows.h>
 #endif  // defined(OS_WIN)
 
 namespace {
 
@@ skipping 30 matching lines @@
 const float kScaleFactorScales[] = {1.0f, 1.4f, 1.8f, 2.0f};
 COMPILE_ASSERT(ui::NUM_SCALE_FACTORS == arraysize(kScaleFactorScales),
                kScaleFactorScales_incorrect_size);
 const size_t kScaleFactorScalesLength = arraysize(kScaleFactorScales);
 
 std::vector<ui::ScaleFactor>& GetSupportedScaleFactorsInternal() {
   static std::vector<ui::ScaleFactor>* supported_scale_factors =
       new std::vector<ui::ScaleFactor>();
   if (supported_scale_factors->empty()) {
       supported_scale_factors->push_back(ui::SCALE_FACTOR_100P);
-#if defined(OS_MACOSX) && defined(ENABLE_HIDPI)
+#if defined(OS_MACOSX) && !defined(OS_IOS) && defined(ENABLE_HIDPI)

[Nico, 2012/09/14 00:52:19]

How does HiDPI code work on iOS? Seems like you'd always wanted to add 200P on
iOS?

[rohitrao (ping after 24h), 2012/09/14 01:07:18]

This bit is TBD; I still need to work out exactly which scale factors I want. 
Was planning to do this in a future CL.

(The scale factor on iOS will never change at runtime, so what I really want is
only 100P on some devices, and only 200P on others.  Will anything break if I
don't add 100P as a supported scale factor?)

[Nico, 2012/09/14 01:13:37]

SGTM. Can you add a "TODO: Figure out ios" comment?
I don't know. But it can probably made work if it doesn't.

[rohitrao (ping after 24h), 2012/09/14 01:30:29]

Added a TODO.  I'll be looking at this either tomorrow or next week, so I'll let
you know if I run into trouble.

       if (base::mac::IsOSLionOrLater())
         supported_scale_factors->push_back(ui::SCALE_FACTOR_200P);
 #elif defined(OS_WIN) && defined(ENABLE_HIDPI)
       if (base::win::IsMetroProcess() && base::win::IsTouchEnabled()) {
         supported_scale_factors->push_back(ui::SCALE_FACTOR_140P);
         supported_scale_factors->push_back(ui::SCALE_FACTOR_180P);
       }
 #elif defined(USE_ASH)
       supported_scale_factors->push_back(ui::SCALE_FACTOR_200P);
 #endif
@@ skipping 70 matching lines @@
   return GetScaleFactorFromScale(
       root_window->compositor()->device_scale_factor());
 #else
   NOTIMPLEMENTED();
   return SCALE_FACTOR_NONE;
 #endif
 }
 #endif  // !defined(OS_MACOSX)
 
 }  // namespace ui