Fix ChromeSwitchCompat thumb drawable and tint color

This is a temporary workaround until we can roll the support library with
their fixes for these issues.

BUG=455327

Review URL: https://codereview.chromium.org/912533003

Cr-Commit-Position: refs/heads/master@{#315434}

chrome/android/java/res/color/switch_thumb_tint.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2015 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(twellington): remove after support library is rolled to pick up their fix for
+                         the thumb drawable not always being visible (crbug.com/440601).  -->
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:state_enabled="true" android:state_checked="true"
+          android:color="@color/pref_accent_color" />
+    <item android:state_enabled="true" android:state_checked="false"
+          android:color="#ececec" />
+    <item android:color="#b9b9b9" />
+</selector>
\ No newline at end of file

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

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2015 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(twellington): remove after support library is rolled to pick up their fix for
+                         the thumb drawable not always being visible (crbug.com/440601).  -->
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:state_checked="true" android:drawable="@drawable/btn_switch_to_on_mtrl_00012" />
+    <item android:drawable="@drawable/btn_switch_to_on_mtrl_00001" />
+</selector>
\ No newline at end of file

chrome/android/java/src/org/chromium/chrome/browser/widget/ChromeSwitchCompat.java

@@ -5,12 +5,17 @@
 package org.chromium.chrome.browser.widget;
 
 import android.content.Context;
+import android.content.res.ColorStateList;
+import android.graphics.PorterDuff;
+import android.graphics.drawable.Drawable;
 import android.support.v7.widget.SwitchCompat;
 import android.util.AttributeSet;
 import android.view.accessibility.AccessibilityEvent;
 import android.view.accessibility.AccessibilityNodeInfo;
 import android.widget.Switch;
 
+import org.chromium.chrome.R;
+
 /**
  * This class fixes the accessibility of SwitchCompat so it's read as "on switch" instead of
  * "checkbox checked". http://crbug.com/441702
@@ -19,15 +24,24 @@ import android.widget.Switch;
  * "Checkbox". This works around the bug by marking accessibility events from SwitchCompat with the
  * Switch class name, which TalkBack recognizes.
  *
+ * It also fixes the thumb drawable being too small and disappearing on certain devices
+ * and the disabled tint color being incorrect. http://crbug.com/455327
+ *
  * TODO(newt): Delete this class once the support library is fixed. http://b/19110477
  */
 public class ChromeSwitchCompat extends SwitchCompat {
+    private Drawable mThumbDrawable;
+    private ColorStateList mTint;
 
     /**
      * Constructor for inflating from XML.
      */
     public ChromeSwitchCompat(Context context, AttributeSet attrs) {
         super(context, attrs);
+        setThumbResource(R.drawable.switch_thumb);
+        mThumbDrawable = getThumbDrawable();
+        mThumbDrawable.mutate();
+        mTint = getResources().getColorStateList(R.color.switch_thumb_tint);
     }
 
     @Override
@@ -41,4 +55,17 @@ public class ChromeSwitchCompat extends SwitchCompat {
         super.onInitializeAccessibilityNodeInfo(info);
         info.setClassName(Switch.class.getName());
     }
+
+    @Override
+    protected void drawableStateChanged() {
+        super.drawableStateChanged();
+        updateThumbTintColor();
+    }
+
+    private boolean updateThumbTintColor() {
+        if (mTint == null) return false;
+        mThumbDrawable.setColorFilter(mTint.getColorForState(mThumbDrawable.getState(), 0),
+                PorterDuff.Mode.SRC_IN);
+        return true;
+    }
 }