Update incognito NTP header color

Update the incognito NTP header color to 100% white.

BUG=850138

Change-Id: Ieb13f4dafeb3af67048904cb80798dff9505bbeb
Reviewed-on: https://chromium-review.googlesource.com/c/1277787Reviewed-by: Becky Zhou <huayinz@chromium.org>
Commit-Queue: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#598924}

chrome/android/java/res/layout/new_tab_page_incognito.xml

@@ -45,9 +45,8 @@
                 android:id="@+id/ntp_incognito_header"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
-                android:fontFamily="sans-serif-light"
                 android:text="@string/new_tab_incognito_header"
-                android:textAppearance="@style/WhiteHeadlineIncognito" />
+                android:textAppearance="@style/WhiteHeadline" />
 
             <TextView
                 android:id="@+id/new_tab_incognito_message"

chrome/android/java/res/layout/new_tab_page_incognito_md.xml

@@ -42,7 +42,7 @@
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:text="@string/new_tab_otr_title"
-                android:textAppearance="@style/WhiteHeadlineIncognito" />
+                android:textAppearance="@style/WhiteHeadline" />
 
             <TextView
                 android:id="@+id/new_tab_incognito_subtitle"

chrome/android/java/res/values-v17/styles.xml

@@ -718,8 +718,6 @@
         <item name="android:textAppearance">@style/BlueButtonText1</item>
         <item name="android:padding">16dp</item>
       </style>
-    <!-- TODO(https://crbug.com/850138): Confirm with UX whether this should be a one-off text
-         appearance or a pre-defined text appearance. -->
     <style name="TextAppearance.IncognitoNewTabLearnMoreLinkModern">
         <item name="android:textColor">@color/modern_blue_300</item>
         <item name="android:textSize">@dimen/text_size_medium</item>

ui/android/java/res/values-v17/styles.xml

@@ -110,10 +110,6 @@
         <item name="android:textColor">@android:color/white</item>
         <item name="android:textSize">@dimen/headline_size</item>
     </style>
-    <style name="WhiteHeadlineIncognito" tools:ignore="UnusedResources">
-        <item name="android:textColor">@color/modern_grey_300</item>
-        <item name="android:textSize">@dimen/headline_size</item>
-    </style>
     <style name="WhiteBodyIncognito" tools:ignore="UnusedResources">
         <item name="android:textColor">@color/white_alpha_70</item>
         <item name="android:textSize">@dimen/text_size_medium</item>

ui/android/java/res/values/colors.xml

@@ -27,7 +27,7 @@
     <color name="modern_grey_50" tools:ignore="UnusedResources">#F8F9FA</color>
     <color name="modern_grey_100" tools:ignore="UnusedResources">#F1F3F4</color>
     <color name="modern_grey_200" tools:ignore="UnusedResources">#E8EAED</color>
-    <color name="modern_grey_300">#DADCE0</color>
+    <color name="modern_grey_300" tools:ignore="UnusedResources">#DADCE0</color>
     <color name="modern_grey_400" tools:ignore="UnusedResources">#BDC1C6</color>
     <color name="modern_grey_500" tools:ignore="UnusedResources">#9AA0A6</color>
     <color name="modern_grey_600" tools:ignore="UnusedResources">#80868B</color>