Makes ui::GetSupportedScaleFactors available on platforms other than Mac

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(USE_AURA) && defined(USE_X11)
 #include "ui/base/touch/touch_factory.h"
 #endif // defined(USE_AURA) && defined(USE_X11)
 
+#if defined(OS_MACOSX)
+#include "base/mac/mac_util.h"
+#endif
+
 #if defined(OS_WIN)
 #include "base/win/metro.h"
 #include <Windows.h>
 #endif  // defined(OS_WIN)
 
 namespace {
 
 // Helper function that determines whether we want to optimize the UI for touch.
 bool UseTouchOptimizedUI() {
   // If --touch-optimized-ui is specified and not set to "auto", then override
@@ skipping 36 matching lines @@
 
   return has_touch_device;
 #else
   return false;
 #endif
 }
 
 const float kScaleFactorScales[] = {1.0, 2.0};
 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 (base::mac::IsOSLionOrLater())
+        supported_scale_factors->push_back(ui::SCALE_FACTOR_200P);
+#elif defined(USE_ASH)
+      supported_scale_factors->push_back(ui::SCALE_FACTOR_200P);
+#endif
+  }
+  return *supported_scale_factors;
+}
+
 }  // namespace
 
 namespace ui {
 
 // Note that this function should be extended to select
 // LAYOUT_TOUCH when appropriate on more platforms than just
 // Windows and Ash.
 DisplayLayout GetDisplayLayout() {
 #if defined(USE_ASH)
   if (UseTouchOptimizedUI())
@@ skipping 18 matching lines @@
       smallest_diff = diff;
     }
   }
   return static_cast<ui::ScaleFactor>(closest_match);
 }
 
 float GetScaleFactorScale(ScaleFactor scale_factor) {
   return kScaleFactorScales[scale_factor];
 }
 
+std::vector<ScaleFactor> GetSupportedScaleFactors() {
+  return GetSupportedScaleFactorsInternal();
+}
+
+bool IsScaleFactorSupported(ScaleFactor scale_factor) {
+  const std::vector<ScaleFactor>& supported =
+      GetSupportedScaleFactorsInternal();
+  return std::find(supported.begin(), supported.end(), scale_factor) !=
+      supported.end();
+}
+
+namespace test {
+
+void SetSupportedScaleFactors(
+    const std::vector<ui::ScaleFactor>& scale_factors) {
+  std::vector<ui::ScaleFactor>& supported_scale_factors =
+      GetSupportedScaleFactorsInternal();
+  supported_scale_factors = scale_factors;
+}
+
+}  // namespace test
+
 #if !defined(OS_MACOSX)
 ScaleFactor GetScaleFactorForNativeView(gfx::NativeView view) {
 #if defined(USE_AURA) && !defined(OS_WIN)
   return GetScaleFactorFromScale(
       view->GetRootWindow()->compositor()->device_scale_factor());
 #else
   NOTIMPLEMENTED();
   return SCALE_FACTOR_NONE;
 #endif
 }
 #endif  // !defined(OS_MACOSX)
 
 }  // namespace ui