Bug 1893949 - Don't use a semi-transparent autofill background. r=issammani

This was needed because we didn't use to override the color of the
textfield, so it needed to work with whatever color was there already.

Now that we enforce the color however, there's no point on it being
semi-transparent.

Add a darker version of the color so that it also works on dark mode
(<input style="color-scheme: dark"> or so).

Now that it's opaque, there's no need for Theme.cpp to blend with the
field background.

Differential Revision: https://phabricator.services.mozilla.com/D209021

modules/libpref/init/all.js

@@ -509,19 +509,6 @@ pref("ui.textHighlightBackground", "#ef0fff");
 // The foreground color for the matched text in findbar highlighting
 // Used with nsISelectionController::SELECTION_FIND
 pref("ui.textHighlightForeground", "#ffffff");
-// The background color for :autofill-ed inputs.
-//
-// In the past, we used the following `filter` to paint autofill backgrounds:
-//
-//   grayscale(21%) brightness(88%) contrast(161%) invert(10%) sepia(40%) saturate(206%);
-//
-// but there are some pages where using `filter` caused issues because it
-// changes the z-order (see bug 1687682, bug 1727950).
-//
-// The color is chosen so that you get the same final color on a white
-// background as the filter above (#fffcc8), but with some alpha so as to
-// prevent fully illegible text.
-pref("ui.-moz-autofill-background", "rgba(255, 249, 145, .5)");
 
 // We want the ability to forcibly disable platform a11y, because
 // some non-a11y-related components attempt to bring it up.  See bug

widget/Theme.cpp

@@ -296,6 +296,9 @@ std::pair<sRGBColor, sRGBColor> Theme::ComputeButtonColors(
   bool isHovered = aState.HasState(ElementState::HOVER);
 
   nscolor backgroundColor = [&] {
+    if (aState.HasState(ElementState::AUTOFILL)) {
+      return aColors.SystemNs(StyleSystemColor::MozAutofillBackground);
+    }
     if (isDisabled) {
       return aColors.SystemNs(StyleSystemColor::MozButtondisabledface);
     }
@@ -308,12 +311,6 @@ std::pair<sRGBColor, sRGBColor> Theme::ComputeButtonColors(
     return aColors.SystemNs(StyleSystemColor::Buttonface);
   }();
 
-  if (aState.HasState(ElementState::AUTOFILL)) {
-    backgroundColor = NS_ComposeColors(
-        backgroundColor,
-        aColors.SystemNs(StyleSystemColor::MozAutofillBackground));
-  }
-
   const sRGBColor borderColor =
       ComputeBorderColor(aState, aColors, OutlineCoversBorder::Yes);
   return std::make_pair(sRGBColor::FromABGR(backgroundColor), borderColor);
@@ -323,18 +320,15 @@ std::pair<sRGBColor, sRGBColor> Theme::ComputeTextfieldColors(
     const ElementState& aState, const Colors& aColors,
     OutlineCoversBorder aOutlineCoversBorder) {
   nscolor backgroundColor = [&] {
+    if (aState.HasState(ElementState::AUTOFILL)) {
+      return aColors.SystemNs(StyleSystemColor::MozAutofillBackground);
+    }
     if (aState.HasState(ElementState::DISABLED)) {
       return aColors.SystemNs(StyleSystemColor::MozDisabledfield);
     }
     return aColors.SystemNs(StyleSystemColor::Field);
   }();
 
-  if (aState.HasState(ElementState::AUTOFILL)) {
-    backgroundColor = NS_ComposeColors(
-        backgroundColor,
-        aColors.SystemNs(StyleSystemColor::MozAutofillBackground));
-  }
-
   const sRGBColor borderColor =
       ComputeBorderColor(aState, aColors, aOutlineCoversBorder);
   return std::make_pair(sRGBColor::FromABGR(backgroundColor), borderColor);

widget/cocoa/nsLookAndFeel.mm

@@ -353,6 +353,7 @@ nsresult nsLookAndFeel::NativeGetColor(ColorID aID, ColorScheme aScheme,
     case ColorID::SpellCheckerUnderline:
     case ColorID::Activeborder:
     case ColorID::Inactiveborder:
+    case ColorID::MozAutofillBackground:
       aColor = GetStandinForNativeColor(aID, aScheme);
       return NS_OK;
     default:

widget/gtk/nsLookAndFeel.cpp

@@ -800,6 +800,7 @@ nsresult nsLookAndFeel::PerThemeData::GetColor(ColorID aID,
     case ColorID::SpellCheckerUnderline:
     case ColorID::Mark:
     case ColorID::Marktext:
+    case ColorID::MozAutofillBackground:
       aColor = GetStandinForNativeColor(
           aID, mIsDark ? ColorScheme::Dark : ColorScheme::Light);
       break;

widget/nsXPLookAndFeel.cpp

@@ -711,6 +711,7 @@ nscolor nsXPLookAndFeel::GetStandinForNativeColor(ColorID aID,
       // Seems to be the default color (hardcoded because of bug 1065998)
       COLOR(MozNativehyperlinktext, 0x00, 0x66, 0xCC)
       COLOR(MozNativevisitedhyperlinktext, 0x55, 0x1A, 0x8B)
+      COLOR(MozAutofillBackground, 0xff, 0xfc, 0xc8)
     default:
       break;
   }
@@ -855,6 +856,11 @@ Maybe<nscolor> nsXPLookAndFeel::GenericDarkColor(ColorID aID) {
     case ColorID::Inactivecaption:
       color = NS_RGB(28, 27, 34);
       break;
+    case ColorID::MozAutofillBackground:
+      // This is the light version of this color, but darkened to have good
+      // contrast with our white-ish FieldText.
+      color = NS_RGB(0x72, 0x6c, 0x00);
+      break;
     default:
       return Nothing();
   }

widget/windows/nsLookAndFeel.cpp

@@ -364,6 +364,7 @@ nsresult nsLookAndFeel::NativeGetColor(ColorID aID, ColorScheme aScheme,
     case ColorID::Marktext:
     case ColorID::Mark:
     case ColorID::SpellCheckerUnderline:
+    case ColorID::MozAutofillBackground:
       aColor = GetStandinForNativeColor(aID, aScheme);
       return NS_OK;
     default: