Herb: Show an icon allowing the user to open a tab in Chrome

chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java
index 265f36545028202e4e0f601fb3ac3a3c38d6442d..8734ed066524356f6ec92b26753d2ec177447534 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java
@@ -48,6 +48,7 @@ import org.chromium.chrome.browser.compositor.layouts.eventfilter.EventFilter;
 import org.chromium.chrome.browser.compositor.layouts.phone.StackLayout;
 import org.chromium.chrome.browser.cookies.CookiesFetcher;
 import org.chromium.chrome.browser.device.DeviceClassManager;
+import org.chromium.chrome.browser.document.ChromeLauncherActivity;
 import org.chromium.chrome.browser.document.DocumentUma;
 import org.chromium.chrome.browser.enhancedbookmarks.EnhancedBookmarkUtils;
 import org.chromium.chrome.browser.firstrun.FirstRunActivity;
@@ -81,6 +82,7 @@ import org.chromium.chrome.browser.tabmodel.TabModelUtils;
 import org.chromium.chrome.browser.tabmodel.TabWindowManager;
 import org.chromium.chrome.browser.toolbar.ToolbarControlContainer;
 import org.chromium.chrome.browser.util.FeatureUtilities;
+import org.chromium.chrome.browser.util.IntentUtils;
 import org.chromium.chrome.browser.widget.emptybackground.EmptyBackgroundViewWrapper;
 import org.chromium.chrome.browser.widget.findinpage.FindToolbarManager;
 import org.chromium.content.browser.ContentVideoView;
@@ -695,7 +697,8 @@ public class ChromeTabbedActivity extends ChromeActivity implements OverviewMode
                     break;
                 case OPEN_NEW_TAB:
                     Tab newTab = launchIntent(url, referer, headers, externalAppId, true, intent);
-                    newTab.setIsAllowedToReturnToExternalApp(true);
+                    newTab.setIsAllowedToReturnToExternalApp(IntentUtils.safeGetBooleanExtra(intent,
+                            ChromeLauncherActivity.EXTRA_IS_ALLOWED_TO_RETURN_TO_PARENT, true));
                     RecordUserAction.record("MobileReceivedExternalIntent");
                     break;
                 case OPEN_NEW_INCOGNITO_TAB:
@@ -1025,7 +1028,8 @@ public class ChromeTabbedActivity extends ChromeActivity implements OverviewMode
 
     /**
      * Closes the foreground tab, potentially sending the user back to the app that launched Chrome.
-     *
+     * TODO(dfalcantara): Come up with a better name for this, given that Herb can prevent the tab
+     *                    from closing.
      * @return Whether the tab closed was opened for a help page.
      */
     private boolean closeForegroundTab() {
@@ -1043,15 +1047,24 @@ public class ChromeTabbedActivity extends ChromeActivity implements OverviewMode
             return true;
         }
 
+        // Check whether Herb allows the tab to close or just forces the app to minimize itself.
+        boolean isAllowedToClose = true;
+        String herbFlavor = ChromePreferenceManager.getHerbFlavor();
+        if (!TextUtils.isEmpty(herbFlavor)) {
+            // Don't close the tab if the return button is showing.
+            isAllowedToClose = !currentTab.isAllowedToReturnToExternalApp();
+            Log.d(TAG, "Herb: Allowing the tab to close: " + isAllowedToClose);
+        }
+
         // [true]: Reached the bottom of the back stack on a tab the user did not explicitly
         // create (i.e. it was created by an external app or opening a link in background, etc).
         // [false]: Reached the bottom of the back stack on a tab that the user explicitly
         // created (e.g. selecting "new tab" from menu).
-        final boolean shouldCloseTab = type == TabLaunchType.FROM_LINK
+        final boolean shouldCloseTab = isAllowedToClose && (type == TabLaunchType.FROM_LINK
                 || type == TabLaunchType.FROM_EXTERNAL_APP
                 || type == TabLaunchType.FROM_LONGPRESS_FOREGROUND
                 || type == TabLaunchType.FROM_LONGPRESS_BACKGROUND
-                || (type == TabLaunchType.FROM_RESTORE && parentId != Tab.INVALID_TAB_ID);
+                || (type == TabLaunchType.FROM_RESTORE && parentId != Tab.INVALID_TAB_ID));
 
         // Minimize the app if either:
         // - we decided not to close the tab