Add callout for the tab switcher button

chrome/android/java/res/anim/text_bubble_in.xml

Index: chrome/android/java/res/anim/text_bubble_in.xml
diff --git a/chrome/android/java/res/anim/text_bubble_in.xml b/chrome/android/java/res/anim/text_bubble_in.xml
new file mode 100644
index 0000000000000000000000000000000000000000..41eaf6cc80edb43d4718aebaa3bd24258f7f8e10
--- /dev/null
+++ b/chrome/android/java/res/anim/text_bubble_in.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c) 2016 The Chromium Authors. All rights reserved.

[Ted C, 2016/04/21 16:31:48]

no (c)

[gone, 2016/04/21 21:18:25]

Done.

+     Use of this source code is governed by a BSD-style license that can be
+     found in the LICENSE file.
+-->
+
+<set xmlns:android="http://schemas.android.com/apk/res/android"
+    android:duration="@android:integer/config_mediumAnimTime"
+    android:interpolator="@android:interpolator/fast_out_slow_in" >

[Ted C, 2016/04/21 16:31:48]

this looks like it only exists in api 21+

http://developer.android.com/reference/android/R.interpolator.html#fast_out_s...

is it added via the support library before that?

[gone, 2016/04/21 21:18:26]

Yes, but there's no obvious way to trigger it.  Reached out to
android-chatty-eng, but the (currently only) person who responded said it wasn't
possible.  Made it so that the bubble could only appear for SDK level 21 and
above as a concession.

+
+    <alpha
+        android:fromAlpha="0"
+        android:toAlpha="1.0" />
+
+    <translate
+        android:fromYDelta="-10"

[Ted C, 2016/04/21 16:31:48]

by default is this px or dp?

[gone, 2016/04/21 21:18:26]

px; apparently you can't define DP for animations:

http://developer.android.com/guide/topics/resources/animation-resource.html

+        android:toYDelta="0" />
+
+</set>