[ios] Updates styling for the IncognitoView.

Screenshots: https://bugs.chromium.org/p/chromium/issues/detail?id=805521#c11

BUG=805521,805522

Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Iee04f09c04a95a58368ee8cd9b51448729b437aa
Reviewed-on: https://chromium-review.googlesource.com/1101218Reviewed-by: Justin Cohen <justincohen@chromium.org>
Commit-Queue: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567637}

ios/chrome/browser/ui/ntp/BUILD.gn

@@ -137,6 +137,7 @@ source_set("ntp_internal") {
     "resources:bookmarks_button_border",
     "resources:disclosure_open",
     "resources:incognito_icon",
+    "resources:incognito_legacy_icon",
     "resources:ntp_bookmarks",
     "resources:ntp_bottom_bar_shadow",
     "resources:ntp_delete_button",

ios/chrome/browser/ui/ntp/resources/BUILD.gn

@@ -192,6 +192,15 @@ imageset("incognito_icon") {
   ]
 }
 
+imageset("incognito_legacy_icon") {
+  sources = [
+    "incognito_legacy_icon.imageset/Contents.json",
+    "incognito_legacy_icon.imageset/incognito_legacy_icon.png",
+    "incognito_legacy_icon.imageset/incognito_legacy_icon@2x.png",
+    "incognito_legacy_icon.imageset/incognito_legacy_icon@3x.png",
+  ]
+}
+
 imageset("ntp_opentabs_recent_arrow") {
   sources = [
     "ntp_opentabs_recent_arrow.imageset/Contents.json",

ios/chrome/browser/ui/ntp/resources/incognito_legacy_icon.imageset/Contents.json

+{
+    "images": [
+        {
+            "idiom": "universal",
+            "scale": "1x",
+            "filename": "incognito_legacy_icon.png"
+        },
+        {
+            "idiom": "universal",
+            "scale": "2x",
+            "filename": "incognito_legacy_icon@2x.png"
+        },
+        {
+            "idiom": "universal",
+            "scale": "3x",
+            "filename": "incognito_legacy_icon@3x.png"
+        }
+    ],
+    "info": {
+        "version": 1,
+        "author": "xcode"
+    }
+}