[iOS][Dark Mode] Add special color for omnibox incognito background

As an additional incognito distinguisher, design added a special
background color for the omnibox in incognito mode.

Bug: 976645
Change-Id: I002db2657f028ee3796d39ed9a715003f7d8a2e3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1744149Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Commit-Queue: Robbie Gibson <rkgibson@google.com>
Cr-Commit-Position: refs/heads/master@{#685176}

ios/chrome/browser/ui/toolbar/buttons/BUILD.gn

@@ -25,6 +25,7 @@ source_set("buttons") {
     "toolbar_type.h",
   ]
   deps = [
+    "resources:omnibox_incognito_background_color",
     "resources:tab_toolbar_button_color_highlighted",
     "resources:tab_toolbar_button_color_highlighted_incognito",
     "resources:tab_toolbar_button_halo_color",

ios/chrome/browser/ui/toolbar/buttons/resources/BUILD.gn

@@ -4,6 +4,12 @@
 
 import("//build/config/ios/asset_catalog.gni")
 
+colorset("omnibox_incognito_background_color") {
+  sources = [
+    "omnibox_incognito_background_color.colorset/Contents.json",
+  ]
+}
+
 colorset("tab_toolbar_button_color_highlighted") {
   sources = [
     "tab_toolbar_button_color_highlighted.colorset/Contents.json",

ios/chrome/browser/ui/toolbar/buttons/resources/omnibox_incognito_background_color.colorset/Contents.json

+{
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  },
+  "colors" : [
+    {
+      "idiom" : "universal",
+      "color" : {
+        "color-space" : "display-p3",
+        "components" : {
+          "red" : "0x20",
+          "alpha" : "1.000",
+          "blue" : "0x24",
+          "green" : "0x21"
+        }
+      }
+    }
+  ]
+}
\ No newline at end of file

ios/chrome/browser/ui/toolbar/buttons/toolbar_configuration.mm

@@ -68,12 +68,16 @@
 }
 
 - (UIColor*)locationBarBackgroundColorWithVisibility:(CGFloat)visibilityFactor {
-  return color::IncognitoDynamicColor(
-      self.style == INCOGNITO,
-      [[UIColor colorNamed:kTextfieldBackgroundColor]
-          colorWithAlphaComponent:visibilityFactor],
-      [[UIColor colorNamed:kTextfieldBackgroundDarkColor]
-          colorWithAlphaComponent:visibilityFactor]);
+  // For the omnibox specifically, the background should be different in
+  // incognito compared to dark mode.
+  switch (self.style) {
+    case NORMAL:
+      return [[UIColor colorNamed:kTextfieldBackgroundColor]
+          colorWithAlphaComponent:visibilityFactor];
+    case INCOGNITO:
+      return [[UIColor colorNamed:@"omnibox_incognito_background_color"]
+          colorWithAlphaComponent:visibilityFactor];
+  }
 }
 
 @end