Fix broken VR transitions due to ChromeTabbedActivity not being exported.

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 35 matching lines @@
     <uses-permission android:name="android.permission.READ_SYNC_SETTINGS"/>
     <uses-permission android:name="android.permission.READ_SYNC_STATS"/>
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
     <uses-permission android:name="android.permission.RECORD_AUDIO"/>
     <uses-permission android:name="android.permission.USE_CREDENTIALS"/>
     <uses-permission android:name="android.permission.VIBRATE"/>
     <uses-permission android:name="android.permission.WAKE_LOCK"/>
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
     <uses-permission android:name="android.permission.WRITE_SYNC_SETTINGS"/>
     {% set enable_vr_shell = enable_vr_shell|default(0) %}
-    {% if enable_vr_shell == "true" %}
+    {% set enable_webvr = enable_webvr|default(0) %}
+    {% if enable_vr_shell == "true" or enable_webvr == "true" %}
     <!-- Required to read the paired viewer's distortion parameters. -->
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
     <!-- Indicates use of Android's VR-mode, available only on Android N+. -->
     <uses-feature android:name="android.software.vr.mode" android:required="false"/>
     <!-- Indicates use of VR features that are available only on Daydream-ready devices. -->
     <uses-feature android:name="android.hardware.vr.high_performance" android:required="false"/>
     {% endif %}
 
     <permission android:name="{{ manifest_package }}.permission.CHILD_SERVICE" android:protectionLevel="signature" />
     <permission android:name="{{ manifest_package }}.permission.READ_WRITE_BOOKMARK_FOLDERS" android:protectionLevel="signatureOrSystem" />
@@ skipping 273 matching lines @@
             android:windowSoftInputMode="adjustResize"
             android:persistableMode="persistNever"
             android:taskAffinity=""
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|mcc|mnc|screenLayout|smallestScreenSize"
             android:hardwareAccelerated="false">
         </activity>
         {% 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" %}
+            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">
+            <!--
+              See the VRChromeTabbedActivity alias below for an explanation of this dummy intent
+              filter. We need to add these filters here as well, or non-presenting webVR pages will
+              trigger a daydream incompatible app message.
+            -->
             <intent-filter>
-                <!-- Add a dummy action to match intent without any action. -->
                 <action android:name="org.chromium.chrome.browser.dummy.action" />
-                <!--
-                  Daydream api categorizes an activity to three categories: Cardboard only, hybrid
-                  or Daydream. It does so by testing if intents can be resolved by the activity
-                  that requests it.
-                  In Chrome, CTA is the activity that uses Daydream api and we want to be in hybrid
-                  category. So add an intent filter that could pass Daydream tests here.
-                -->
                 <category android:name="com.google.intent.category.DAYDREAM" />
                 <category android:name="com.google.intent.category.CARDBOARD" />
             </intent-filter>
-            {% endif %}
         </activity>
+
+        {% if enable_vr_shell == "true" or enable_webvr == "true" %}
+        <!--
+            TODO(mthiesse): Temporarily skip ChromeLauncherActivity when returning from Daydream
+            DON flow to avoid polluting metrics.
+        -->
+        <activity-alias android:name="org.chromium.chrome.browser.VRChromeTabbedActivity"
+            android:targetActivity="org.chromium.chrome.browser.ChromeTabbedActivity"
+            android:exported="true"

[Ted C, 2016/11/16 18:07:00]

Sorry, but I don't think we can/should do this.

By doing this, external applications will be able to send intents directly to
ChromeTabbedActivity (if they hardcode the classname as that bypasses the intent
filters).

This means any sanitizing of intents we do in ChromeLauncher would be skipped,
which is why we don't export our activities as it ensures a single place to do
this.

Also, it would allow third parties to change Chrome's behavior by bypassing our
access point.

[mthiesse, 2016/11/16 18:45:12]

Ah, yes thanks for pointing that out. I've switched to using pendingIntents and
their API seems to be fine with that.

The alias is no longer exported, though we should keep it around for the
enableVrMode flag so that the transition is less jarring.

+            android:enableVrMode="@string/gvr_vr_mode_component">
+            <!--
+              Daydream api categorizes an activity to three categories: Cardboard only, hybrid
+              or Daydream. It does so by testing if intents can be resolved by the activity
+              that requests it.
+              In Chrome, CTA is the activity that uses Daydream api and we want to be in hybrid
+              category. So add an intent filter that could pass Daydream tests here.
+            -->
+            <intent-filter>
+                <action android:name="org.chromium.chrome.browser.dummy.action" />
+                <category android:name="com.google.intent.category.DAYDREAM" />
+                <category android:name="com.google.intent.category.CARDBOARD" />
+            </intent-filter>
+        </activity-alias>
+        {% endif %}
+
         <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>
         <activity android:name="org.chromium.chrome.browser.multiwindow.MultiInstanceChromeTabbedActivity"
@@ skipping 546 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>