[Home] Ensure incognito tab model is created when NTP opened

chrome/android/java/src/org/chromium/chrome/browser/tabmodel/IncognitoTabModel.java

Index: chrome/android/java/src/org/chromium/chrome/browser/tabmodel/IncognitoTabModel.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/tabmodel/IncognitoTabModel.java b/chrome/android/java/src/org/chromium/chrome/browser/tabmodel/IncognitoTabModel.java
index 6ce844fcf5c4c4c90433cf73e2a93ab3895ca534..3c435a8da4b2c753d8dd67cce9f2ad353ff5ada0 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/tabmodel/IncognitoTabModel.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/tabmodel/IncognitoTabModel.java
@@ -36,6 +36,7 @@ public class IncognitoTabModel implements TabModel {
     private final ObserverList<TabModelObserver> mObservers = new ObserverList<TabModelObserver>();
     private TabModel mDelegateModel;
     private boolean mIsAddingTab;
+    private boolean mMayAddTab;
 
     /**
      * Constructor for IncognitoTabModel.
@@ -72,7 +73,7 @@ public class IncognitoTabModel implements TabModel {
      */
     protected void destroyIncognitoIfNecessary() {
         ThreadUtils.assertOnUiThread();
-        if (!isEmpty() || mDelegateModel instanceof EmptyTabModel || mIsAddingTab) {
+        if (!isEmpty() || mDelegateModel instanceof EmptyTabModel || mIsAddingTab || mMayAddTab) {
             return;
         }
 
@@ -212,6 +213,7 @@ public class IncognitoTabModel implements TabModel {
     @Override
     public void addTab(Tab tab, int index, TabLaunchType type) {
         mIsAddingTab = true;
+        mMayAddTab = false;
         ensureTabModelImpl();
         mDelegateModel.addTab(tab, index, type);
         mIsAddingTab = false;
@@ -241,4 +243,13 @@ public class IncognitoTabModel implements TabModel {
     public void openMostRecentlyClosedTab() {
     }
 
+    @Override
+    public void setMayAddTab(boolean mayAddTab) {

[Ted C, 2017/05/23 23:50:17]

What happens if you are multi-window, you open two incognito tabs in one.  Open
the incognito chrome home panel in the other, then click the close all incognito
notification?

I think it might leave this tab model with a reference to a destroyed profile. 
I think we need to expose this boolean and add a new function to
TabWindowManager (canDestroyIncognitoProfile) that would check this.

From a UI standpoint, should clicking the incognito notification should it close
any open incognito chrome home panels?

[Theresa, 2017/05/24 16:52:08]

That path was causing issues (crashes on a segfault in bookmarks code). I added
the suggested TabWindowManager#canDestroyIncognitoProfile and now the incognito
profile isn't destructed when still in use.
Yes, I think that any open CH panels on top of incognito tabs should be closed.
I added some code to IncognitoNotificationService to close the bottom sheet if
the incognito ntp is showing.

+        mMayAddTab = mayAddTab;
+        if (mMayAddTab) {
+            ensureTabModelImpl();
+        } else {
+            destroyIncognitoIfNecessary();
+        }
+    }
 }