Fix: long-tapping a WebAPK in recents shows Chrome.

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 527 matching lines @@
         <activity-alias android:name="com.google.android.apps.chrome.webapps.WebappActivity"
             android:targetActivity="org.chromium.chrome.browser.webapps.WebappActivity"
             android:label="@string/webapp_activity_title"
             {{ self.supports_video_persistence() }} >
         </activity-alias>
         {% for i in range(10) %}
         <activity android:name="org.chromium.chrome.browser.webapps.WebappActivity{{ i }}"
             android:theme="@style/WebappTheme"
             android:icon="@mipmap/app_shortcut_icon"
             android:label="@string/webapp_activity_title"
             android:launchMode="singleTask"

[Yaron, 2017/03/23 15:29:53]

Hmm, I worry that us deviating from this may lead to unexpected bugs. That said,
there is a different interaction model for WebApks. That said, I see that
CustomTabs also uses singleTask.

[Xi Han, 2017/03/23 21:07:42]

I don't know why singleTask is just doesn't work for WebApkActivity. When they
are started without new_task or new_document flags, they are supposed to on top
of the WebappLauncherActivity and in the same task. But this isn't true for
WebApkActivity, Android always creates a new task stack for it.

             android:windowSoftInputMode="adjustResize"
             android:persistableMode="persistNever"
             android:hardwareAccelerated="false"
             android:taskAffinity="{{ manifest_package }}.webapps.WebappActivity{{ i }}"
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|mcc|mnc|screenLayout|smallestScreenSize"
             {{ self.supports_video_persistence() }} >
         </activity>
         <activity-alias android:name="com.google.android.apps.chrome.webapps.WebappActivity{{ i }}"
             android:targetActivity="org.chromium.chrome.browser.webapps.WebappActivity{{ i }}"
             android:icon="@mipmap/app_shortcut_icon"
             android:label="@string/webapp_activity_title">
         </activity-alias>
         {% endfor %}
         <!-- Activities for WebAPKs. -->
         <activity android:name="org.chromium.chrome.browser.webapps.WebApkActivity"
             android:theme="@style/WebappTheme"
             android:label="@string/webapp_activity_title"
             android:launchMode="singleTop"
-            android:documentLaunchMode="intoExisting"
             android:windowSoftInputMode="adjustResize"
             android:persistableMode="persistNever"
             android:hardwareAccelerated="false"
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|mcc|mnc|screenLayout|smallestScreenSize"
             {{ self.supports_video_persistence() }} >
         </activity>
         {% for i in range(10) %}
         <activity android:name="org.chromium.chrome.browser.webapps.WebApkActivity{{ i }}"
             android:theme="@style/WebappTheme"
             android:icon="@mipmap/app_shortcut_icon"
             android:label="@string/webapp_activity_title"
-            android:launchMode="singleTask"
+            android:launchMode="singleTop"

[Ted C, 2017/03/23 23:16:07]

The assigner pretty strongly assumes a 1:1 relationship, and this breaks that in
all types of ways.  This has to remain singleTask if you want the existing logic
to work.

[Xi Han, 2017/03/24 16:05:36]

I think only a WebAPK will launch a WebApkAcitivity instance, and each WebAPK
will have its own WebApkAcitvity since the meta-date in the Intent to start the
activity is unique for each WebAPK. Beside, we have a launcher class
WebappLauncherActivity to launch the WebApkActivityXXX, the activity launching
order is:
 WebAPK's main activity -> WebappLauncherActivity -> WebApkActivityXXX (has a
suffix number on KK)

Do you think it will really break by changing to singleTop ? 

             android:windowSoftInputMode="adjustResize"
             android:persistableMode="persistNever"
             android:hardwareAccelerated="false"
             android:taskAffinity="{{ manifest_package }}.webapps.WebApkActivity{{ i }}"
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|mcc|mnc|screenLayout|smallestScreenSize"
             {{ self.supports_video_persistence() }} >
         </activity>
         {% endfor %}
 
         <activity android:name="org.chromium.chrome.browser.media.remote.ExpandedControllerActivity"
@@ skipping 377 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>