[Home] Select "Home" content when NTP UI shown

Previously if the sheet was open and another BottomSheetContent was
displayed, opening a new tab (e.g. via a launcher shortcut) did not
switch to the "Home" content.

BUG=743066

Change-Id: Ib1dc72c1e301e31685580e334a0b5da0f2719dd5
Reviewed-on: https://chromium-review.googlesource.com/572040Reviewed-by: Matthew Jones <mdjones@chromium.org>
Commit-Queue: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487323}

chrome/android/java/src/org/chromium/chrome/browser/widget/bottomsheet/BottomSheet.java

@@ -778,7 +778,7 @@ public class BottomSheet
         mToolbarHolder = (FrameLayout) mControlContainer.findViewById(R.id.toolbar_holder);
         mDefaultToolbarView = (BottomToolbarPhone) mControlContainer.findViewById(R.id.toolbar);
 
-        mNtpController = new BottomSheetNewTabController(this, mDefaultToolbarView);
+        mNtpController = new BottomSheetNewTabController(this, mDefaultToolbarView, mActivity);
 
         mActivity.getFullscreenManager().addListener(new FullscreenListener() {
             @Override

chrome/android/java/src/org/chromium/chrome/browser/widget/bottomsheet/BottomSheetContentController.java

@@ -223,6 +223,16 @@ public class BottomSheetContentController extends BottomNavigationView
         mDefaultContentInitialized = true;
     }
 
+    /**
+     * @param itemId The id of the MenuItem to select.
+     */
+    public void selectItem(int itemId) {
+        // TODO(twellington): A #setSelectedItemId() method was added to the support library
+        //                    recently. Replace this custom implementation with that method after
+        //                    the support library is rolled.
+        onNavigationItemSelected(getMenu().findItem(itemId));
+    }
+
     /**
      * Shows the specified {@link BottomSheetContent} and opens the {@link BottomSheet}.
      * @param itemId The menu item id of the {@link BottomSheetContent} to show.
@@ -346,17 +356,6 @@ public class BottomSheetContentController extends BottomNavigationView
         setItemTextColor(tint);
     }
 
-    /**
-     * @param itemId The id of the MenuItem to select.
-     */
-    @VisibleForTesting
-    public void selectItem(int itemId) {
-        // TODO(twellington): A #setSelectedItemId() method was added to the support library
-        //                    recently. Replace this custom implementation with that method after
-        //                    the support library is rolled.
-        onNavigationItemSelected(getMenu().findItem(itemId));
-    }
-
     @VisibleForTesting
     public int getSelectedItemIdForTests() {
         // TODO(twellington): A #getSelectedItemId() method was added to the support library

chrome/android/java/src/org/chromium/chrome/browser/widget/bottomsheet/BottomSheetNewTabController.java

@@ -4,6 +4,8 @@
 
 package org.chromium.chrome.browser.widget.bottomsheet;
 
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.ChromeActivity;
 import org.chromium.chrome.browser.compositor.layouts.EmptyOverviewModeObserver;
 import org.chromium.chrome.browser.compositor.layouts.LayoutManagerChrome;
 import org.chromium.chrome.browser.compositor.layouts.OverviewModeBehavior.OverviewModeObserver;
@@ -13,12 +15,11 @@ import org.chromium.chrome.browser.toolbar.BottomToolbarPhone;
 
 /**
  * A class that handles showing and hiding the Chrome Home new tab UI.
- *
- * TODO(twellington): Add tests for this class.
  */
 public class BottomSheetNewTabController extends EmptyBottomSheetObserver {
     private final BottomSheet mBottomSheet;
     private final BottomToolbarPhone mToolbar;
+    private final ChromeActivity mActivity;
 
     private LayoutManagerChrome mLayoutManager;
     private OverviewModeObserver mOverviewModeObserver;
@@ -34,11 +35,14 @@ public class BottomSheetNewTabController extends EmptyBottomSheetObserver {
      * @param bottomSheet The {@link BottomSheet} that will be opened as part of the new tab UI.
      * @param toolbar The {@link BottomToolbarPhone} that this controller will set state on as part
      *                of the new tab UI.
+     * @param activity The {@link ChromeActivity} containing the {@link BottomSheet}.
      */
-    public BottomSheetNewTabController(BottomSheet bottomSheet, BottomToolbarPhone toolbar) {
+    public BottomSheetNewTabController(
+            BottomSheet bottomSheet, BottomToolbarPhone toolbar, ChromeActivity activity) {
         mBottomSheet = bottomSheet;
         mBottomSheet.addObserver(this);
         mToolbar = toolbar;
+        mActivity = activity;
     }
 
     /**
@@ -92,14 +96,19 @@ public class BottomSheetNewTabController extends EmptyBottomSheetObserver {
         // Tell the model that a new tab may be added soon.
         mTabModelSelector.getModel(isIncognito).setIsPendingTabAdd(true);
 
-        // Select the correct model, immediately ending animations so that the sheet content is not
-        // in transition while the sheet is opening.
+        // Select the correct model, immediately ending animations so that the previous sheet
+        // content is not in use while calling #setIsPendingTabAdd() on previous model.
         if (mTabModelSelector.isIncognitoSelected() != isIncognito) {
             mTabModelSelector.selectModel(isIncognito);
             mBottomSheet.endTransitionAnimations();
             mTabModelSelector.getModel(!isIncognito).setIsPendingTabAdd(false);
         }
 
+        // Select the correct sheet content, immediately ending animations so that the sheet content
+        // is not in transition while the sheet is opening.
+        mActivity.getBottomSheetContentController().selectItem(R.id.action_home);
+        mBottomSheet.endTransitionAnimations();
+
         // Open the sheet if it isn't already open to the desired height.
         int sheetState = mTabModelSelector.getCurrentModel().getCount() == 0
                 ? BottomSheet.SHEET_STATE_FULL