Revert static member LayoutThemeDefault cleanup.

Making the selection colors and caret interval members non-static
members of LayoutThemeDefault in [1] caused regressions for the devtools
inspector because GetTheme() returns different objects depending on
whether we emulate a mobile device or not, and these values are only
updated on the current object returned by LayoutTheme::GetTheme().

Also added a test to avoid this regression in the future.

[1] https://crrev.com/67575409937d6cc6d2226f7f5bcea667075e5d7d

Bug: 1062214
Change-Id: I06144fb4ff74e204432591498e7cd2e934018819
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2106070
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Reviewed-by: Morten Stenshorne <mstensho@chromium.org>
Cr-Commit-Position: refs/heads/master@{#751273}

third_party/blink/renderer/core/layout/layout_theme_default.cc

@@ -46,10 +46,16 @@ static const float kDefaultCancelButtonSize = 9;
 static const float kMinCancelButtonSize = 5;
 static const float kMaxCancelButtonSize = 21;
 
-LayoutThemeDefault::LayoutThemeDefault()
-    : LayoutTheme(),
-      caret_blink_interval_(LayoutTheme::CaretBlinkInterval()),
-      painter_(*this) {}
+base::TimeDelta LayoutThemeDefault::caret_blink_interval_;
+
+Color LayoutThemeDefault::active_selection_background_color_ = 0xff1e90ff;
+Color LayoutThemeDefault::active_selection_foreground_color_ = Color::kBlack;
+Color LayoutThemeDefault::inactive_selection_background_color_ = 0xffc8c8c8;
+Color LayoutThemeDefault::inactive_selection_foreground_color_ = 0xff323232;
+
+LayoutThemeDefault::LayoutThemeDefault() : LayoutTheme(), painter_(*this) {
+  caret_blink_interval_ = LayoutTheme::CaretBlinkInterval();
+}
 
 LayoutThemeDefault::~LayoutThemeDefault() = default;
 

third_party/blink/renderer/core/layout/layout_theme_default.h

@@ -150,12 +150,13 @@ class CORE_EXPORT LayoutThemeDefault : public LayoutTheme {
   int MenuListInternalPadding(const ComputedStyle&, int padding) const;
 
   static const RGBA32 kDefaultTapHighlightColor = 0x2e000000;  // 18% black.
-  base::TimeDelta caret_blink_interval_;
 
-  Color active_selection_background_color_ = 0xff1e90ff;
-  Color active_selection_foreground_color_ = Color::kBlack;
-  Color inactive_selection_background_color_ = 0xffc8c8c8;
-  Color inactive_selection_foreground_color_ = 0xff323232;
+  static base::TimeDelta caret_blink_interval_;
+
+  static Color active_selection_background_color_;
+  static Color active_selection_foreground_color_;
+  static Color inactive_selection_background_color_;
+  static Color inactive_selection_foreground_color_;
 
   ThemePainterDefault painter_;
   // Cached values for crbug.com/673754.

third_party/blink/renderer/core/layout/layout_theme_test.cc

@@ -80,8 +80,8 @@ TEST_F(LayoutThemeTest, ChangeFocusRingColor) {
   EXPECT_EQ(custom_color, OutlineColor(span));
 }
 
-// The expectations are based on LayoutThemeDefault::SystemColor.
-// LayoutThemeMac doesn't use that code path.
+// The expectations in the tests below are relying on LayoutThemeDefault.
+// LayoutThemeMac doesn't inherit from that class.
 #if !defined(OS_MACOSX)
 TEST_F(LayoutThemeTest, SystemColorWithColorScheme) {
   SetHtmlInnerHTML(R"HTML(
@@ -112,6 +112,32 @@ TEST_F(LayoutThemeTest, SystemColorWithColorScheme) {
   EXPECT_EQ(Color(0x44, 0x44, 0x44),
             style->VisitedDependentColor(GetCSSPropertyColor()));
 }
+
+TEST_F(LayoutThemeTest, SetSelectionColors) {
+  LayoutTheme::GetTheme().SetSelectionColors(Color::kBlack, Color::kBlack,
+                                             Color::kBlack, Color::kBlack);
+  EXPECT_EQ(Color::kBlack,
+            LayoutTheme::GetTheme().ActiveSelectionForegroundColor(
+                WebColorScheme::kLight));
+  {
+    // Enabling MobileLayoutTheme switches which instance is returned from
+    // LayoutTheme::GetTheme(). Devtools expect SetSelectionColors() to affect
+    // both LayoutTheme instances.
+    ScopedMobileLayoutThemeForTest scope(true);
+    EXPECT_EQ(Color::kBlack,
+              LayoutTheme::GetTheme().ActiveSelectionForegroundColor(
+                  WebColorScheme::kLight));
+
+    LayoutTheme::GetTheme().SetSelectionColors(Color::kWhite, Color::kWhite,
+                                               Color::kWhite, Color::kWhite);
+    EXPECT_EQ(Color::kWhite,
+              LayoutTheme::GetTheme().ActiveSelectionForegroundColor(
+                  WebColorScheme::kLight));
+  }
+  EXPECT_EQ(Color::kWhite,
+            LayoutTheme::GetTheme().ActiveSelectionForegroundColor(
+                WebColorScheme::kLight));
+}
 #endif  // !defined(OS_MACOSX)
 
 }  // namespace blink