Don't acquire getTitle() if Tab has been destroyed in PseudoTab

Now with fields such as Title being migrated to UserData objects
we enforce that the attribute cannot be acquired after destroy()
has been called. Unfortunately, in PseuoTab getTitle() was called
after destroy() causing the app to crash which is an invalid
assumption. This CL adds an isInitialized() check before the
getTitle() call.

Bug: 1114564
Change-Id: I064ae7d3601d45116cb198885ef64ff42a2aac7d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2346785Reviewed-by: Yusuf Ozuysal <yusufo@chromium.org>
Commit-Queue: David Maunder <davidjm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#796431}

chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/pseudotab/PseudoTab.java

@@ -162,7 +162,7 @@ public class PseudoTab {
      * @return The title
      */
     public String getTitle() {
-        if (mTab != null && mTab.get() != null) {
+        if (mTab != null && mTab.get() != null && mTab.get().isInitialized()) {
             return mTab.get().getTitle();
         }
         assert mTabId != null;

chrome/android/features/tab_ui/junit/src/org/chromium/chrome/browser/tasks/pseudotab/PseudoTabUnitTest.java

@@ -427,7 +427,7 @@ public class PseudoTabUnitTest {
     }
 
     @Test
-    public void testTabDestroyed() {
+    public void testTabDestroyedRootId() {
         Tab tab = new MockTab(TAB4_ID, false);
         PseudoTab pseudoTab = PseudoTab.fromTab(tab);
         tab.destroy();
@@ -436,4 +436,15 @@ public class PseudoTabUnitTest {
         // UnsupportedOperationException
         Assert.assertEquals(Tab.INVALID_TAB_ID, pseudoTab.getRootId());
     }
+
+    @Test
+    public void testTabDestroyedTitle() {
+        Tab tab = new MockTab(TAB4_ID, false);
+        PseudoTab pseudoTab = PseudoTab.fromTab(tab);
+        tab.destroy();
+        // Title was not set. Without the isInitialized() check,
+        // pseudoTab.getTitle() would crash here with
+        // UnsupportedOperationException
+        Assert.assertEquals("", pseudoTab.getTitle());
+    }
 }