Android: Fix gesture navigation arrow UI on KitKat

This CL a partial revert of https://crrev.com/c/1771638 so that
the removed vector drawable can be used on KitKat instead of
9-patch drawable. KitKit doesn't seem to handle scaling 9-patch
drawable well. Using the vector drawable gets around the issue.

Bug: 993506
Change-Id: Id7b8db13ea2e19e3e3e3fed83b42c84cea9a95d8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1826748
Commit-Queue: Jinsuk Kim <jinsukkim@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#701008}

chrome/android/java/res/drawable/navigation_bubble_shadow.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2019 The Chromium Authors. All rights reserved.
+     Use of this source code is governed by a BSD-style license that can be
+     found in the LICENSE file. -->
+
+<!-- TODO(crbug.com/1009058): Remove this with KitKiat deprecation. -->
+
+<layer-list
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/navigation_bubble_shadow">
+
+    <!-- Drop Shadow -->
+    <item>
+        <shape android:shape="rectangle">
+            <padding
+                android:bottom="@dimen/navigation_bubble_shadow_padding"
+                android:left="@dimen/navigation_bubble_shadow_padding"
+                android:right="@dimen/navigation_bubble_shadow_padding"
+                android:top="@dimen/navigation_bubble_shadow_padding" />
+
+            <corners android:radius="@dimen/navigation_bubble_radius" />
+            <solid android:color="#00CCCCCC" />
+
+        </shape>
+    </item>
+    <item>
+        <shape android:shape="rectangle">
+            <padding
+                android:bottom="@dimen/navigation_bubble_shadow_padding"
+                android:left="@dimen/navigation_bubble_shadow_padding"
+                android:right="@dimen/navigation_bubble_shadow_padding"
+                android:top="@dimen/navigation_bubble_shadow_padding" />
+
+            <corners android:radius="@dimen/navigation_bubble_radius" />
+            <solid android:color="#10CCCCCC" />
+        </shape>
+    </item>
+    <item>
+        <shape android:shape="rectangle">
+            <padding
+                android:bottom="@dimen/navigation_bubble_shadow_padding"
+                android:left="@dimen/navigation_bubble_shadow_padding"
+                android:right="@dimen/navigation_bubble_shadow_padding"
+                android:top="@dimen/navigation_bubble_shadow_padding" />
+
+            <corners android:radius="@dimen/navigation_bubble_radius" />
+            <solid android:color="#20CCCCCC" />
+        </shape>
+    </item>
+    <item>
+        <shape android:shape="rectangle">
+            <padding
+                android:bottom="@dimen/navigation_bubble_shadow_padding"
+                android:left="@dimen/navigation_bubble_shadow_padding"
+                android:right="@dimen/navigation_bubble_shadow_padding"
+                android:top="@dimen/navigation_bubble_shadow_padding" />
+
+            <corners android:radius="@dimen/navigation_bubble_radius" />
+            <solid android:color="#30CCCCCC" />
+        </shape>
+    </item>
+    <item>
+        <shape android:shape="rectangle">
+            <padding
+                android:bottom="@dimen/navigation_bubble_shadow_padding"
+                android:left="@dimen/navigation_bubble_shadow_padding"
+                android:right="@dimen/navigation_bubble_shadow_padding"
+                android:top="@dimen/navigation_bubble_shadow_padding" />
+
+            <corners android:radius="@dimen/navigation_bubble_radius" />
+            <solid android:color="#50CCCCCC" />
+        </shape>
+    </item>
+
+    <!-- Background Color (white) -->
+    <item>
+        <shape android:shape="rectangle">
+            <corners android:radius="@dimen/navigation_bubble_radius" />
+            <solid android:color="@color/navigation_bubble_background_color" />
+        </shape>
+    </item>
+</layer-list>

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

@@ -685,6 +685,8 @@
 
     <!-- History Navigation UI Item -->
     <dimen name="navigation_bubble_size">44dp</dimen>
+    <dimen name="navigation_bubble_radius">22dp</dimen>
+    <dimen name="navigation_bubble_shadow_padding">1dp</dimen>
     <dimen name="navigation_bubble_arrow_size">32dp</dimen>
     <dimen name="navigation_bubble_start_padding">2dp</dimen>
     <dimen name="navigation_bubble_top_padding">4dp</dimen>