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

chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappLauncherActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappLauncherActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappLauncherActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappLauncherActivity.java
index 64906a676c9cfc65600c40023b17160cce71b088..cebb6b4760da79494df283f17b6234a8acd31935 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappLauncherActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappLauncherActivity.java
@@ -40,6 +40,12 @@ public class WebappLauncherActivity extends Activity {
 
     private static final String TAG = "webapps";
 
+    /**
+     * We remove android:documentLaunchMode="intoExisting" attribute from WebApkActivity since this
+     * version.
+     */
+    private static final int SHELL_APK_VERSION_BEFROE_REMOVE_DOCUMENT_LAUNCH_MODE = 1;

[gone, 2017/03/22 22:20:07]

BEFORE

+
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -149,11 +155,15 @@ public class WebappLauncherActivity extends Activity {
         launchIntent.setAction(Intent.ACTION_VIEW);
         launchIntent.setData(Uri.parse(WebappActivity.WEBAPP_SCHEME + "://" + info.id()));
 
-        if (!isWebApk) {
-            // For WebAPK, we don't start a new task for WebApkActivity, it is just on top
-            // of the WebAPK's main activity and in the same task.
-            launchIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK
-                    | ApiCompatibilityUtils.getActivityNewDocumentFlag());
+        if ((isWebApk && info instanceof WebApkInfo
+                    && ((WebApkInfo) info).shellApkVersion()
+                            > SHELL_APK_VERSION_BEFROE_REMOVE_DOCUMENT_LAUNCH_MODE)
+                || source == ShortcutSource.NOTIFICATION) {
+            // Since shell APK version 2, we removes the android:documentLaunchMode="intoExisting"
+            // attribute from WebApkActivity. Instead, flag {@link FLAG_ACTIVITY_CLEAR_TOP} is used
+            // to deliver this intent to the WebApkActivity instance if it is already running on the
+            // top of the stack via onNewIntent(). WebApkActivity should be on top of the WebAPK's
+            // main activity in the same task stack. See crbug.com/700157.
 
             // If this is launching from a notification, we want to ensure that the URL being
             // launched is the URL in the intent. If a paused WebappActivity exists for this id,
@@ -162,9 +172,10 @@ public class WebappLauncherActivity extends Activity {
             // the existing Activity is cleared and relaunched with this intent.
             // TODO(dominickn): ideally, we want be able to route an intent to
             // WebappActivity.onNewIntent instead of restarting the Activity.
-            if (source == ShortcutSource.NOTIFICATION) {
-                launchIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
-            }
+            launchIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
+        } else {

[gone, 2017/03/22 22:20:07]

You've changed this logic here so that non WebApks do either the first half of
the statement or the second half, depending on whether you're doing this from a
notification.  Is that intentional?

[gone, 2017/03/22 22:23:28]

Well, I can see how this would stay the same logically.  The other version was
weirdly written so that it would override the flags from the previous call
instead of using an else clause.

+            launchIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK
+                    | ApiCompatibilityUtils.getActivityNewDocumentFlag());
         }
         return launchIntent;
     }