Fix imcompatible app warning when insert to DayDream headset

chrome/android/java/AndroidManifest.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. -->
 
 <!--
 Note: This is a jinja2 template, processed at build time into the final manifest.
 
 Blocks denoted with { % block some_name % }foo{ % endblock % } can be overridden
 by a child template that "extends" this file.
@@ skipping 335 matching lines @@
         {% endfor %}
 
         <!-- ChromeTabbedActivity related -->
         <activity android:name="org.chromium.chrome.browser.ChromeTabbedActivity"
              android:theme="@style/TabbedModeTheme"
              android:exported="false"
              android:windowSoftInputMode="adjustResize"
              android:launchMode="singleTask"
              android:configChanges="orientation|keyboardHidden|keyboard|screenSize|mcc|mnc|screenLayout|smallestScreenSize"
              android:hardwareAccelerated="false">
+            {% set enable_webvr = enable_webvr|default(0) %}
+            {% if enable_vr_shell == "true" or enable_webvr == "true" %}
+            <intent-filter>
+                <!-- Add a dummy action to match intent without any action. -->
+                <action android:name="org.chromium.chrome.browser.dummy.action" />

[Maria, 2016/10/26 20:10:27]

Why does a dummy name allow to match intent without any action?  Why wouldn't
there be an action on the intent?

[bshe, 2016/10/26 20:51:46]

Based on this doc:
https://developer.android.com/guide/components/intents-filters.html#ActionTest
It sounds like in order to pass action test for intent with no action, we need
to have a dummy action here.
 
The way Daydream figure out which category an activity belongs to is to test if
a Daydream category intent can be resolved.
And they didn't add any action when create the intent.

+                <category android:name="com.google.intent.category.DAYDREAM" />

[Maria, 2016/10/26 20:10:27]

Not too familiar with this -- I have a few questions:

1) Wouldn't this put this activity into Daydream launcher? The comment on
ChromeLauncherActivity seems to imply that's a side effect of adding the filter.

2) I imagine only ChromeLauncherActivity and Chrome internally sends intents
against ChromeTabbedActivity, so it's kind of weird that we have an intent
filter here.

[mthiesse, 2016/10/26 20:15:21]

I actually just had a discussion with Biao, and we don't want to be in the
Daydream launcher at all just yet (the cold launch experience is brutal).

Is there any way to fix the incompatible warning without being on the launcher?

[bshe, 2016/10/26 20:51:46]

This won't make Chrome appear in the launcher. To appear in launcher, it
requires
<action android:name="android.intent.action.MAIN" /> in addition to category.

[bshe, 2016/10/26 20:51:46]

So Daydream will try to test if their intents can be resolved by the foreground
activity.
And based on the result, it categorize the activity to Cardboard only, hybrid or
Daydream only.
ChromeLauncherActivity is a transit activity. So I have to add intent filter
here since this
is the activity that actually use Daydream api.

[Maria, 2016/10/26 21:07:24]

Ok, can you add this as a comment here -- I think people reading this later may
find it very surprising that there's an intent filter on a non-exported
activity.

[bshe, 2016/10/27 15:01:15]

Done.

+                <category android:name="com.google.intent.category.CARDBOARD" />
+            </intent-filter>
+            {% endif %}
         </activity>
         <activity android:name="org.chromium.chrome.browser.ChromeTabbedActivity2"
              android:theme="@style/TabbedModeTheme"
              android:exported="false"
              android:windowSoftInputMode="adjustResize"
              android:taskAffinity="{{ manifest_package }}.ChromeTabbedActivity2"
              android:launchMode="singleTask"
              android:configChanges="orientation|keyboardHidden|keyboard|screenSize|mcc|mnc|screenLayout|smallestScreenSize"
              android:hardwareAccelerated="false">
         </activity>
@@ skipping 547 matching lines @@
              choose the first MediaRouteController that can play it, so the order of the list can be important.
              The most specific MediaRouteControllers should be listed first, followed by more generic ones.
              The downstream manifest replaces this block, and hence replaces the list of media route
              controllers with its own list. -->
         <meta-data android:name="org.chromium.content.browser.REMOTE_MEDIA_PLAYERS"
             android:value="org.chromium.chrome.browser.media.remote.DefaultMediaRouteController"/>
 
         {% endblock %}
     </application>
 </manifest>