Simplified GetTabBackgroundColor()

Pushed color calculation logic in GetTabBackgroundColor() down into
ThemeHelper.

Bug: 1056916
Change-Id: I6c6b5a204554b825887b1c306b766e4403609279
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2092199
Commit-Queue: Thomas Lukaszewicz <tluk@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#748889}

chrome/browser/themes/theme_helper.cc

@@ -244,7 +244,19 @@ SkColor ThemeHelper::GetDefaultColor(
     const CustomThemeSupplier* theme_supplier) const {
   // For backward compat with older themes, some newer colors are generated from
   // older ones if they are missing.
+  const auto get_frame_color = [this, incognito, theme_supplier](bool active) {
+    return this->GetColor(active ? TP::COLOR_FRAME : TP::COLOR_FRAME_INACTIVE,
+                          incognito, theme_supplier);
+  };
   switch (id) {
+    case TP::COLOR_BACKGROUND_TAB:
+      return color_utils::HSLShift(get_frame_color(/*active=*/true),
+                                   GetTint(ThemeProperties::TINT_BACKGROUND_TAB,
+                                           incognito, theme_supplier));
+    case TP::COLOR_BACKGROUND_TAB_INACTIVE:
+      return color_utils::HSLShift(get_frame_color(/*active=*/false),
+                                   GetTint(ThemeProperties::TINT_BACKGROUND_TAB,
+                                           incognito, theme_supplier));
     case TP::COLOR_TOOLBAR_BUTTON_ICON:
     case TP::COLOR_TOOLBAR_BUTTON_ICON_HOVERED:
     case TP::COLOR_TOOLBAR_BUTTON_ICON_PRESSED:
@@ -262,10 +274,8 @@ SkColor ThemeHelper::GetDefaultColor(
     case TP::COLOR_TOOLBAR_TOP_SEPARATOR_INACTIVE: {
       const SkColor tab_color =
           GetColor(TP::COLOR_TOOLBAR, incognito, theme_supplier);
-      const int frame_id = (id == TP::COLOR_TOOLBAR_TOP_SEPARATOR)
-                               ? TP::COLOR_FRAME
-                               : TP::COLOR_FRAME_INACTIVE;
-      const SkColor frame_color = GetColor(frame_id, incognito, theme_supplier);
+      const SkColor frame_color =
+          get_frame_color(/*active=*/id == TP::COLOR_TOOLBAR_TOP_SEPARATOR);
       const SeparatorColorKey key(tab_color, frame_color);
       auto i = GetSeparatorColorCache().find(key);
       if (i != GetSeparatorColorCache().end())

chrome/browser/ui/views/tabs/tab_strip.cc

@@ -1908,25 +1908,13 @@ SkColor TabStrip::GetTabBackgroundColor(
   if (active == TabActive::kActive)
     return tp->GetColor(ThemeProperties::COLOR_TOOLBAR);
 
-  bool is_active_frame;
-  if (active_state == BrowserFrameActiveState::kUseCurrent)
-    is_active_frame = ShouldPaintAsActiveFrame();
-  else
-    is_active_frame = active_state == BrowserFrameActiveState::kActive;
-
-  const int color_id = is_active_frame
-                           ? ThemeProperties::COLOR_BACKGROUND_TAB
-                           : ThemeProperties::COLOR_BACKGROUND_TAB_INACTIVE;
-  // When the background tab color has not been customized, use the actual frame
-  // color instead of COLOR_BACKGROUND_TAB.
-  const SkColor frame = controller_->GetFrameColor(active_state);
-  const SkColor background =
-      tp->HasCustomColor(color_id)
-          ? tp->GetColor(color_id)
-          : color_utils::HSLShift(
-                frame, tp->GetTint(ThemeProperties::TINT_BACKGROUND_TAB));
-
-  return background;
+  using State = BrowserFrameActiveState;
+  const bool is_active_frame =
+      (active_state == State::kActive) ||
+      ((active_state == State::kUseCurrent) && ShouldPaintAsActiveFrame());
+  return tp->GetColor(is_active_frame
+                          ? ThemeProperties::COLOR_BACKGROUND_TAB
+                          : ThemeProperties::COLOR_BACKGROUND_TAB_INACTIVE);
 }
 
 SkColor TabStrip::GetTabForegroundColor(TabActive active,