Add a function to layout.h for getting ScaleFactor of the native view.

BUG=125043

Review URL: https://chromiumcodereview.appspot.com/10823067

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@149775 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/renderer_host/render_widget_host_view_mac.mm

@@ -48,6 +48,7 @@
 #include "third_party/skia/include/core/SkColor.h"
 #import "ui/base/cocoa/fullscreen_window_manager.h"
 #import "ui/base/cocoa/underlay_opengl_hosting_window.h"
+#include "ui/base/layout.h"
 #include "ui/gfx/point.h"
 #include "ui/gfx/scoped_ns_graphics_context_save_gstate_mac.h"
 #include "ui/surface/io_surface_support_mac.h"
@@ -74,10 +75,6 @@ using WebKit::WebGestureEvent;
 + (void)removeMonitor:(id)eventMonitor;
 @end
 
-@interface NSScreen (LionAPI)
-- (CGFloat)backingScaleFactor;
-@end
-
 @interface NSWindow (LionAPI)
 - (CGFloat)backingScaleFactor;
 @end
@@ -110,17 +107,7 @@ static inline int ToWebKitModifiers(NSUInteger flags) {
 }
 
 static float ScaleFactor(NSView* view) {
-  if (NSWindow* window = [view window]) {
-    if ([window respondsToSelector:@selector(backingScaleFactor)])
-      return [window backingScaleFactor];
-    return [window userSpaceScaleFactor];
-  }
-  if (NSScreen* screen = [NSScreen mainScreen]) {
-    if ([screen respondsToSelector:@selector(backingScaleFactor)])
-      return [screen backingScaleFactor];
-    return [screen userSpaceScaleFactor];
-  }
-  return 1;
+  return ui::GetScaleFactorScale(ui::GetScaleFactorForNativeView(view));
 }
 
 // Private methods:

ui/base/layout.cc

@@ -13,6 +13,11 @@
 #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)
@@ -73,18 +78,6 @@ bool UseTouchOptimizedUI() {
 const float kScaleFactorScales[] = {1.0, 2.0};
 const size_t kScaleFactorScalesLength = arraysize(kScaleFactorScales);
 
-#if defined(OS_MACOSX)
-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);
-      supported_scale_factors->push_back(ui::SCALE_FACTOR_200P);
-  }
-  return *supported_scale_factors;
-}
-#endif  // OS_MACOSX
-
 }  // namespace
 
 namespace ui {
@@ -123,25 +116,16 @@ float GetScaleFactorScale(ScaleFactor scale_factor) {
   return kScaleFactorScales[scale_factor];
 }
 
-#if defined(OS_MACOSX)
-std::vector<ScaleFactor> GetSupportedScaleFactors() {
-  return GetSupportedScaleFactorsInternal();
-}
-
-namespace test {
-
-void SetSupportedScaleFactors(
-    const std::vector<ui::ScaleFactor>& scale_factors) {
-  std::vector<ui::ScaleFactor>& supported_scale_factors =
-      GetSupportedScaleFactorsInternal();
-  supported_scale_factors.clear();
-
-  for (size_t i = 0; i < scale_factors.size(); ++i)
-    supported_scale_factors.push_back(scale_factors[i]);
+#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
 }
-
-}  // namespace test
-
-#endif  // OS_MACOSX
+#endif  // !defined(OS_MACOSX)
 
 }  // namespace ui

ui/base/layout.h

@@ -9,6 +9,7 @@
 
 #include "build/build_config.h"
 #include "ui/base/ui_export.h"
+#include "ui/gfx/native_widget_types.h"
 
 namespace ui {
 
@@ -49,6 +50,9 @@ UI_EXPORT float GetScaleFactorScale(ScaleFactor scale_factor);
 // little as possible.
 UI_EXPORT ScaleFactor GetScaleFactorFromScale(float scale);
 
+// Returns the ScaleFactor used by |view|.
+UI_EXPORT ScaleFactor GetScaleFactorForNativeView(gfx::NativeView view);
+
 #if defined(OS_MACOSX)
 
 // Returns a vector with the scale factors which are supported by this

ui/base/layout_mac.mm

+// 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 <Cocoa/Cocoa.h>
+
+@interface NSScreen (LionAPI)
+- (CGFloat)backingScaleFactor;
+@end
+
+@interface NSWindow (LionAPI)
+- (CGFloat)backingScaleFactor;
+@end
+
+namespace {
+
+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);
+    supported_scale_factors->push_back(ui::SCALE_FACTOR_200P);
+  }
+  return *supported_scale_factors;
+}
+
+float GetScaleFactorScaleForNativeView(gfx::NativeView view) {
+  float scale_factor = 1.0f;
+  if (NSWindow* window = [view window]) {
+    if ([window respondsToSelector:@selector(backingScaleFactor)])
+      return [window backingScaleFactor];
+    scale_factor = [window userSpaceScaleFactor];
+  }
+  if (NSScreen* screen = [NSScreen mainScreen]) {
+    if ([screen respondsToSelector:@selector(backingScaleFactor)])
+      return [screen backingScaleFactor];
+    return [screen userSpaceScaleFactor];
+  }
+  return 1.0f;
+}
+
+}  // namespace
+
+namespace ui {
+
+ScaleFactor GetScaleFactorForNativeView(gfx::NativeView view) {
+  return GetScaleFactorFromScale(GetScaleFactorScaleForNativeView(view));
+}
+
+std::vector<ScaleFactor> GetSupportedScaleFactors() {
+  return GetSupportedScaleFactorsInternal();
+}
+
+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
+
+}  // namespace ui

ui/ui.gyp

@@ -218,6 +218,7 @@
         'base/l10n/l10n_util_win.h',
         'base/layout.cc',
         'base/layout.h',
+        'base/layout_mac.mm',
         'base/models/button_menu_item_model.cc',
         'base/models/button_menu_item_model.h',
         'base/models/combobox_model.h',