Fix broken VR transitions due to ChromeTabbedActivity not being exported.

chrome/android/java/AndroidManifest.xml

Index: chrome/android/java/AndroidManifest.xml
diff --git a/chrome/android/java/AndroidManifest.xml b/chrome/android/java/AndroidManifest.xml
index 8140934fed7cb21f19220a1e188fda1778abb307..e27a8a6048d180cad9b98442b671b791371ccfb9 100644
--- a/chrome/android/java/AndroidManifest.xml
+++ b/chrome/android/java/AndroidManifest.xml
@@ -53,7 +53,8 @@ by a child template that "extends" this file.
     <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+. -->
@@ -354,29 +355,47 @@ by a child template that "extends" this file.
 
         <!-- 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: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"