Change fonts for FRE welcome screen to default font

Changing fonts to fix the glitch on the welcome screen, as Google Sans
might be not available yet for the first screen.

Bug: 1119990
Change-Id: Ia0e939c651b105357215357db6038ab2d10a5031
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2425383
Commit-Queue: Wenyu Fu <wenyufu@chromium.org>
Reviewed-by: Lijin Shen <lazzzis@google.com>
Reviewed-by: Sky Malice <skym@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#809859}

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

@@ -44,7 +44,7 @@
                 <TextView
                     android:id="@+id/title"
                     android:text="@string/fre_welcome"
-                    style="@style/FreTitle" />
+                    style="@style/FreWelcomePageTitle" />
 
                 <!-- The FrameLayout here is to facilitate adding a proper content description for
                  the loading view. During development, it didn't seem possible to override the
@@ -124,7 +124,7 @@
             android:paddingEnd="@dimen/fre_button_padding"
             android:text="@string/fre_accept_continue"
             android:animateLayoutChanges="true"
-            style="@style/FilledButton.Flat" />
+            style="@style/FreAcceptTosButton" />
 
         <!-- Same location as the button; marginBottom is adjusted for the different size. -->
         <ProgressBar

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

@@ -227,6 +227,14 @@
     </style>
 
     <!-- First Run Experience -->
+    <!-- Avoid using @font/accent_font, a downloaded font, on text that could appear in the first
+         couple of frames of app start. It may not be ready yet, see https://crbug.com/1119990 -->
+    <style name="TextAppearance.FreFirstFrameTitle" parent="TextAppearance.Headline.Primary" >
+        <item name="android:fontFamily">sans-serif</item>
+    </style>
+    <style name="TextAppearance.FreFirstFrameButton" parent="TextAppearance.Button.Text.Filled">
+        <item name="android:fontFamily">sans-serif</item>
+    </style>
     <style name="FreTitle">
         <item name="android:layout_width">wrap_content</item>
         <item name="android:layout_height">wrap_content</item>
@@ -234,6 +242,12 @@
         <item name="android:lineSpacingMultiplier">1.4</item>
         <item name="android:textAppearance">@style/TextAppearance.Headline.Primary</item>
     </style>
+    <style name="FreWelcomePageTitle" parent="FreTitle">
+        <item name="android:textAppearance">@style/TextAppearance.FreFirstFrameTitle</item>
+    </style>
+    <style name="FreAcceptTosButton" parent="FilledButton.Flat">
+        <item name="android:textAppearance">@style/TextAppearance.FreFirstFrameButton</item>
+    </style>
 
     <!-- Web Notifications -->
     <style name="TextAppearance.Notification"