Add PhysicalWebBroadcastService

chrome/android/java/src/org/chromium/chrome/browser/physicalweb/PhysicalWebShareActivity.java

 // Copyright 2017 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.
 
 package org.chromium.chrome.browser.physicalweb;
 
+import android.content.Intent;
 import android.os.Build;
 
 import org.chromium.chrome.browser.ChromeActivity;
 import org.chromium.chrome.browser.share.ShareActivity;
 
 /**
  * A simple activity that allows Chrome to start the physical web sharing service.
  */
 public class PhysicalWebShareActivity extends ShareActivity {
     @Override
     protected void handleShareAction(ChromeActivity triggeringActivity) {

[nyquist, 2017/03/06 22:34:14]

Should this be protected by some finch flag? Or is that at a different level?

[iankc, 2017/03/07 02:10:39]

This is protected in the featureIsAvailable() method below, that uses a finch
feature flag to tell if it should be enabled. The finch feature flag lives in
PhysicalWeb.sharingIsEnabled() method.

[nyquist, 2017/03/07 06:58:33]

Acknowledged.

-        // TODO(iankc): implement this.
+        String url = triggeringActivity.getActivityTab().getUrl();

[nyquist, 2017/03/06 22:34:14]

Can the activity tab ever be null? Say the user taps the tab switcher
immediately after hitting share or some other weird edge-case?

[iankc, 2017/03/07 02:10:40]

Yes, the activity tab can be null! However, in the ShareActivity (the abstract
class that this activity inherits from) it checks to make sure it's not null
before calling handleShareAction.
https://cs.corp.google.com/clankium/src/chrome/android/java/src/org/chromium/...

[nyquist, 2017/03/07 06:58:33]

Acknowledged.

+
+        Intent intent = new Intent(this, PhysicalWebBroadcastService.class);
+        intent.putExtra(PhysicalWebBroadcastService.DISPLAY_URL_KEY, url);
+        startService(intent);

[nyquist, 2017/03/06 22:34:14]

Is this guaranteed to only pinky-promise be called while Chrome is still in the
foreground?

[iankc, 2017/03/07 02:10:39]

This should only be called when chrome is in the foreground. The only way to
call onCreate() is through the share picker, which has to be in the foreground.
Also, we handle for when the triggering chromeActivity is null, which might also
handle this case. 

[nyquist, 2017/03/07 06:58:33]

Acknowledged.

     }
 
+    /**
+     * Returns whether we should show this sharing option in the share sheet.
+     * Pre-conditions for Physical Web Sharing to be enabled:
+     *      Device is Marshmallow or above.
+     *      Device has sharing feature enabled.
+     */

[nyquist, 2017/03/06 22:34:14]

Would probably be helpful with a @return here. (remember empty line to separate
the two for readability)

[iankc, 2017/03/07 02:10:39]

Done.

     public static boolean featureIsAvailable() {
         return PhysicalWeb.sharingIsEnabled() && Build.VERSION.SDK_INT >= Build.VERSION_CODES.M;
     }
 }