Support "display": "fullscreen" for sites added to the home screen.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
index 7a35c67a8ce7a90cbdfc875aec890b77f31d55d4..4cb6ef51634a089c540711cd134431b8f1da50ca 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
@@ -119,8 +119,11 @@ public class WebappActivity extends FullScreenActivity {
         getActivityTab().addObserver(createTabObserver());
         getActivityTab().getTabWebContentsDelegateAndroid().setDisplayMode(
                 WebDisplayMode.Standalone);

[dominickn, 2017/01/16 22:49:01]

Nit: this should be:

getActivityTab().getTabWebContentsDelegateAndroid().setDisplayMode(
        mWebappInfo.displayMode());

[Leo, 2017/01/18 05:09:40]

Thanks for the tips. So what will happen if the display mode was MinimalUi?
Is there any logic to fallback to standalone safely?

[dominickn, 2017/01/18 05:56:17]

Currently, minimal-ui does not open a WebappActivity (it just opens an ordinary
browser tab), so we don't need to worry about a fallback. When we move to
implementing minimal-ui, we'll add the appropriate logic in here. :)

[Leo, 2017/01/18 23:03:12]

Thanks for the explanation. Good to know that.

-        // TODO(dominickn): send the web app into fullscreen if mDisplayMode is
-        // WebDisplayMode.Fullscreen. See crbug.com/581522
+        if (mWebappInfo.displayMode() == WebDisplayMode.Fullscreen) {
+            enterImmersiveMode(getWindow().getDecorView());
+            getActivityTab().getTabWebContentsDelegateAndroid().setDisplayMode(
+                    WebDisplayMode.Fullscreen);
+        }
     }
 
     @Override