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 d6f74bcde7396435f410b9c4333ca0b24ad235da..e191095fa096a84b222711c92d4bbbe7817243b7 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
@@ -39,6 +39,12 @@ public class WebappLauncherActivity extends Activity {
     public static final String ACTION_START_WEBAPP =
             "com.google.android.apps.chrome.webapps.WebappManager.ACTION_START_WEBAPP";
 
+    /**
+     * We remove android:documentLaunchMode="intoExisting" attribute from WebApkActivity since this
+     * version.
+     */
+    private static final int SHELL_APK_VERSION_BEFORE_REMOVE_DOCUMENT_LAUNCH_MODE = 1;
+
     private static final String TAG = "webapps";
 
     @Override
@@ -150,9 +156,21 @@ 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.
+        if (isWebApk && info instanceof WebApkInfo) {
+            // Since shell APK version 2, we removes the android:documentLaunchMode="intoExisting"
+            // attribute from WebApkActivity. Instead, flag {@link FLAG_ACTIVITY_SINGLE_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
+            // {@link ShellActivity} in the same task stack on L+. See crbug.com/700157.
+            if ((((WebApkInfo) info).shellApkVersion()
+                        > SHELL_APK_VERSION_BEFORE_REMOVE_DOCUMENT_LAUNCH_MODE)
+                    && (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)) {
+                launchIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
+            } else {
+                launchIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK

[Yaron, 2017/03/29 14:07:33]

doesn't this change behaviour pre-L? We didn't use to specify this.

[Xi Han, 2017/03/29 15:16:43]

Rewrite the logic here to make the skd version check go first. I guess it is
because on pre-L, singleTask always creates a new task for WebApkActivity{i}, so
it doesn't matter whether we set the flags or not.

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