macviews: support "increase contrast" system setting

This change:
1) Adds NativeTheme::UsesHighContrastColors(), which returns whether special
   high contrast colors should be used, based on system settings;
2) Adds a new --force-high-contrast switch to override the system settings;
3) Adds overrides for certain colors to use black or GoogleBlue900 as needed;
4) Adds gfx::kGoogleBlue900 from the Polymer color specs

Bug: 565996
Change-Id: Ie63f4d965a62bcfdb092660673b52534ce4507dd
Reviewed-on: https://chromium-review.googlesource.com/761316Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523846}

chrome/browser/themes/theme_service.cc

@@ -492,7 +492,7 @@ SkColor ThemeService::GetDefaultColor(int id, bool incognito) const {
           ui::GetAuraColor(id == ThemeProperties::COLOR_TAB_THROBBER_SPINNING
                                ? ui::NativeTheme::kColorId_ThrobberSpinningColor
                                : ui::NativeTheme::kColorId_ThrobberWaitingColor,
-                           nullptr);
+                           ui::NativeTheme::GetInstanceForNativeUi());
       color_utils::HSL hsl = GetTint(ThemeProperties::TINT_BUTTONS, incognito);
       return color_utils::HSLShift(base_color, hsl);
     }

chrome/browser/ui/views/harmony/harmony_typography_provider.cc

@@ -31,10 +31,9 @@ namespace {
 // in Windows 10 still has black text, but (since the user wants high contrast)
 // the grey text shades in Harmony should not be used.
 bool ShouldIgnoreHarmonySpec(const ui::NativeTheme& theme) {
-#if defined(OS_WIN)
-  if (ui::NativeThemeWin::IsUsingHighContrastTheme())
+  if (theme.UsesHighContrastColors())
     return true;
-#endif
+
   constexpr auto kTestColorId = ui::NativeTheme::kColorId_LabelEnabledColor;
   return theme.GetSystemColor(kTestColorId) != SK_ColorBLACK;
 }

chrome/browser/win/titlebar_config.cc

@@ -14,7 +14,7 @@ bool ShouldCustomDrawSystemTitlebar() {
   // mode so that we can correctly draw the caption buttons on the left in RTL
   // mode. But they require a different style and color selection that isn't
   // currently implemented.
-  return !ui::NativeThemeWin::IsUsingHighContrastTheme() &&
+  return !ui::NativeTheme::GetInstanceForNativeUi()->UsesHighContrastColors() &&
          base::CommandLine::ForCurrentProcess()->HasSwitch(
              switches::kWindows10CustomTitlebar) &&
          base::win::GetVersion() >= base::win::VERSION_WIN10;

ui/base/ui_base_switches.cc

@@ -53,6 +53,11 @@ const char kDisableTouchDragDrop[] = "disable-touch-drag-drop";
 // Enables touch event based drag and drop.
 const char kEnableTouchDragDrop[] = "enable-touch-drag-drop";
 
+// Forces high-contrast mode in native UI drawing, regardless of system
+// settings. Note that this has limited effect on Windows: only Aura colors will
+// be switched to high contrast, not other system colors.
+const char kForceHighContrast[] = "force-high-contrast";
+
 // TODO(dcastagna): Draw debug quad borders only when it is actually
 // an overlay candidate.
 // Renders a border around GL composited overlay candidate quads to

ui/base/ui_base_switches.h

@@ -38,6 +38,7 @@ UI_BASE_EXPORT extern const char kDisableTouchAdjustment[];
 UI_BASE_EXPORT extern const char kDisableTouchDragDrop[];
 UI_BASE_EXPORT extern const char kEnableDrawOcclusion[];
 UI_BASE_EXPORT extern const char kEnableTouchDragDrop[];
+UI_BASE_EXPORT extern const char kForceHighContrast[];
 UI_BASE_EXPORT extern const char kGlCompositedOverlayCandidateQuadBorder[];
 UI_BASE_EXPORT extern const char kLang[];
 UI_BASE_EXPORT extern const char kMaterialDesignInkDropAnimationSpeed[];

ui/gfx/color_palette.h

@@ -20,6 +20,7 @@ const SkColor kChromeIconGrey = SkColorSetRGB(0x5A, 0x5A, 0x5A);
 const SkColor kGoogleBlue300 = SkColorSetRGB(0x7B, 0xAA, 0xF7);
 const SkColor kGoogleBlue500 = SkColorSetRGB(0x42, 0x85, 0xF4);
 const SkColor kGoogleBlue700 = SkColorSetRGB(0x33, 0x67, 0xD6);
+const SkColor kGoogleBlue900 = SkColorSetRGB(0x1C, 0x3A, 0xA9);
 const SkColor kGoogleRed300 = SkColorSetRGB(0xE6, 0x7C, 0x73);
 const SkColor kGoogleRed700 = SkColorSetRGB(0xC5, 0x39, 0x29);
 const SkColor kGoogleGreen300 = SkColorSetRGB(0x57, 0xBB, 0x8A);

ui/native_theme/common_theme.cc

@@ -20,6 +20,31 @@ namespace ui {
 
 SkColor GetAuraColor(NativeTheme::ColorId color_id,
                      const NativeTheme* base_theme) {
+  // High contrast overrides the normal colors for certain ColorIds to be much
+  // darker or lighter.
+  if (base_theme->UsesHighContrastColors()) {
+    switch (color_id) {
+      case NativeTheme::kColorId_ButtonEnabledColor:
+      case NativeTheme::kColorId_ButtonHoverColor:
+        return SK_ColorBLACK;
+      case NativeTheme::kColorId_MenuBorderColor:
+      case NativeTheme::kColorId_MenuSeparatorColor:
+        return SK_ColorBLACK;
+      case NativeTheme::kColorId_SeparatorColor:
+        return SK_ColorBLACK;
+      case NativeTheme::kColorId_FocusedBorderColor:
+        return gfx::kGoogleBlue900;
+      case NativeTheme::kColorId_UnfocusedBorderColor:
+        return SK_ColorBLACK;
+      case NativeTheme::kColorId_TabBottomBorder:
+        return SK_ColorBLACK;
+      case NativeTheme::kColorId_ProminentButtonColor:
+        return gfx::kGoogleBlue900;
+      default:
+        break;
+    }
+  }
+
   // Second wave of MD colors (colors that only appear in secondary UI).
   if (ui::MaterialDesignController::IsSecondaryUiMaterial()) {
     static const SkColor kPrimaryTextColor = SK_ColorBLACK;

ui/native_theme/native_theme.h

@@ -420,6 +420,10 @@ class NATIVE_THEME_EXPORT NativeTheme {
   // Notify observers of native theme changes.
   void NotifyObservers();
 
+  // Returns whether this NativeTheme uses higher-contrast colors, controlled by
+  // system accessibility settings and the system theme.
+  virtual bool UsesHighContrastColors() const = 0;
+
  protected:
   NativeTheme();
   virtual ~NativeTheme();

ui/native_theme/native_theme_base.cc

@@ -264,6 +264,11 @@ gfx::Rect NativeThemeBase::GetNinePatchAperture(Part part) const {
   return gfx::Rect();
 }
 
+bool NativeThemeBase::UsesHighContrastColors() const {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kForceHighContrast);
+}
+
 NativeThemeBase::NativeThemeBase()
     : scrollbar_width_(kDefaultScrollbarWidth),
       scrollbar_button_length_(kDefaultScrollbarButtonLength) {

ui/native_theme/native_theme_base.h

@@ -36,6 +36,7 @@ class NATIVE_THEME_EXPORT NativeThemeBase : public NativeTheme {
   bool SupportsNinePatch(Part part) const override;
   gfx::Size GetNinePatchCanvasSize(Part part) const override;
   gfx::Rect GetNinePatchAperture(Part part) const override;
+  bool UsesHighContrastColors() const override;
 
  protected:
   NativeThemeBase();

ui/native_theme/native_theme_mac.h

@@ -45,6 +45,7 @@ class NATIVE_THEME_EXPORT NativeThemeMac : public NativeThemeBase {
       State state,
       const gfx::Rect& rect,
       const MenuItemExtraParams& menu_item) const override;
+  bool UsesHighContrastColors() const override;
 
   // Paints the styled button shape used for default controls on Mac. The basic
   // style is used for dialog buttons, comboboxes, and tabbed pane tabs.

ui/native_theme/native_theme_mac.mm

@@ -16,6 +16,12 @@
 #include "ui/gfx/skia_util.h"
 #include "ui/native_theme/common_theme.h"
 
+@interface NSWorkspace (Redeclarations)
+
+@property(readonly) BOOL accessibilityDisplayShouldIncreaseContrast;
+
+@end
+
 namespace {
 
 // Values calculated by reading pixels and solving simultaneous equations
@@ -283,6 +289,17 @@ void NativeThemeMac::PaintMenuItemBackground(
   }
 }
 
+bool NativeThemeMac::UsesHighContrastColors() const {
+  if (NativeThemeBase::UsesHighContrastColors())
+    return true;
+  NSWorkspace* workspace = [NSWorkspace sharedWorkspace];
+  if ([workspace respondsToSelector:@selector
+                 (accessibilityDisplayShouldIncreaseContrast)]) {
+    return workspace.accessibilityDisplayShouldIncreaseContrast;
+  }
+  return false;
+}
+
 NativeThemeMac::NativeThemeMac() {
 }
 

ui/native_theme/native_theme_win.cc

@@ -10,6 +10,7 @@
 #include <vsstyle.h>
 #include <vssym32.h>
 
+#include "base/command_line.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/win/scoped_gdi_object.h"
@@ -28,6 +29,7 @@
 #include "third_party/skia/include/core/SkShader.h"
 #include "third_party/skia/include/core/SkSurface.h"
 #include "ui/base/material_design/material_design_controller.h"
+#include "ui/base/ui_base_switches.h"
 #include "ui/display/win/screen_win.h"
 #include "ui/gfx/color_palette.h"
 #include "ui/gfx/color_utils.h"
@@ -149,11 +151,6 @@ NativeTheme* NativeTheme::GetInstanceForNativeUi() {
   return NativeThemeWin::instance();
 }
 
-// static
-bool NativeThemeWin::IsUsingHighContrastTheme() {
-  return instance()->IsUsingHighContrastThemeInternal();
-}
-
 // static
 void NativeThemeWin::CloseHandles() {
   instance()->CloseHandlesInternal();
@@ -272,7 +269,7 @@ NativeThemeWin::~NativeThemeWin() {
   }
 }
 
-bool NativeThemeWin::IsUsingHighContrastThemeInternal() {
+bool NativeThemeWin::IsUsingHighContrastThemeInternal() const {
   if (is_using_high_contrast_valid_)
     return is_using_high_contrast_;
   HIGHCONTRAST result;
@@ -514,8 +511,8 @@ SkColor NativeThemeWin::GetSystemColor(ColorId color_id) const {
     case kColorId_TreeSelectionBackgroundFocused:
       return system_colors_[COLOR_HIGHLIGHT];
     case kColorId_TreeSelectionBackgroundUnfocused:
-      return system_colors_[IsUsingHighContrastTheme() ?
-                              COLOR_MENUHIGHLIGHT : COLOR_BTNFACE];
+      return system_colors_[UsesHighContrastColors() ? COLOR_MENUHIGHLIGHT
+                                                     : COLOR_BTNFACE];
 
     // Table
     case kColorId_TableBackground:
@@ -529,8 +526,8 @@ SkColor NativeThemeWin::GetSystemColor(ColorId color_id) const {
     case kColorId_TableSelectionBackgroundFocused:
       return system_colors_[COLOR_HIGHLIGHT];
     case kColorId_TableSelectionBackgroundUnfocused:
-      return system_colors_[IsUsingHighContrastTheme() ?
-                              COLOR_MENUHIGHLIGHT : COLOR_BTNFACE];
+      return system_colors_[UsesHighContrastColors() ? COLOR_MENUHIGHLIGHT
+                                                     : COLOR_BTNFACE];
     case kColorId_TableGroupingIndicatorColor:
       return system_colors_[COLOR_GRAYTEXT];
 
@@ -625,6 +622,12 @@ gfx::Rect NativeThemeWin::GetNinePatchAperture(Part part) const {
   return gfx::Rect();
 }
 
+bool NativeThemeWin::UsesHighContrastColors() const {
+  bool force_enabled = base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kForceHighContrast);
+  return force_enabled || IsUsingHighContrastThemeInternal();
+}
+
 void NativeThemeWin::PaintIndirect(cc::PaintCanvas* destination_canvas,
                                    Part part,
                                    State state,

ui/native_theme/native_theme_win.h

@@ -52,9 +52,6 @@ class NATIVE_THEME_EXPORT NativeThemeWin : public NativeTheme,
     LAST
   };
 
-  // Returns true if a high contrast theme is being used.
-  static bool IsUsingHighContrastTheme();
-
   // Closes cached theme handles so we can unload the DLL or update our UI
   // for a theme change.
   static void CloseHandles();
@@ -78,10 +75,10 @@ class NATIVE_THEME_EXPORT NativeThemeWin : public NativeTheme,
              const gfx::Rect& rect,
              const ExtraParams& extra) const override;
   SkColor GetSystemColor(ColorId color_id) const override;
-
   bool SupportsNinePatch(Part part) const override;
   gfx::Size GetNinePatchCanvasSize(Part part) const override;
   gfx::Rect GetNinePatchAperture(Part part) const override;
+  bool UsesHighContrastColors() const override;
 
  protected:
   friend class NativeTheme;
@@ -92,7 +89,7 @@ class NATIVE_THEME_EXPORT NativeThemeWin : public NativeTheme,
   ~NativeThemeWin() override;
 
  private:
-  bool IsUsingHighContrastThemeInternal();
+  bool IsUsingHighContrastThemeInternal() const;
   void CloseHandlesInternal();
 
   // gfx::SysColorChangeListener implementation:

ui/views/view_unittest.cc

@@ -4790,6 +4790,7 @@ class TestNativeTheme : public ui::NativeTheme {
   gfx::Rect GetNinePatchAperture(Part part) const override {
     return gfx::Rect();
   }
+  bool UsesHighContrastColors() const override { return false; }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TestNativeTheme);