Remove the incorrect assumption about PseudoTab

Remove the incorrect assumption which causes consistent assertion
failure on multi-instance tab merging.

Bug: 1100460, 1080810
Change-Id: Ief512fa3450e0999fdd9588a5ec6b7b6536691d2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2318446Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Commit-Queue: Lijin Shen <lazzzis@google.com>
Cr-Commit-Position: refs/heads/master@{#798179}

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

@@ -86,8 +86,13 @@ public class PseudoTab {
         synchronized (sLock) {
             PseudoTab cached = sAllTabs.get(tab.getId());
             if (cached != null && cached.hasRealTab()) {
-                assert cached.getTab() == tab;
-                return cached;
+                if (cached.getTab() == tab) {
+                    return cached;
+                } else {
+                    assert cached.getTab().getWebContents() == null
+                            || cached.getTab().getWebContents().getTopLevelNativeWindow() == null;
+                    return new PseudoTab(tab);
+                }
             }
             // We need to upgrade a pre-native Tab to a post-native Tab.
             return new PseudoTab(tab);

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

@@ -70,6 +70,7 @@ public class PseudoTabUnitTest {
     private TabImpl mTab1;
     private TabImpl mTab2;
     private TabImpl mTab3;
+    private TabImpl mTab1Copy;
 
     @Before
     public void setUp() {
@@ -78,6 +79,7 @@ public class PseudoTabUnitTest {
         mTab1 = TabUiUnitTestUtils.prepareTab(TAB1_ID, mCriticalPersistedTabData);
         mTab2 = TabUiUnitTestUtils.prepareTab(TAB2_ID, mCriticalPersistedTabData);
         mTab3 = TabUiUnitTestUtils.prepareTab(TAB3_ID, mCriticalPersistedTabData);
+        mTab1Copy = TabUiUnitTestUtils.prepareTab(TAB1_ID, mCriticalPersistedTabData);
 
         doReturn(mTabModelFilterProvider).when(mTabModelSelector).getTabModelFilterProvider();
     }
@@ -139,6 +141,14 @@ public class PseudoTabUnitTest {
         Assert.assertEquals(tab1, tab1prime);
     }
 
+    @Test
+    public void fromTab_obsoleteCache() {
+        PseudoTab tab1 = PseudoTab.fromTab(mTab1);
+        PseudoTab tab1copy = PseudoTab.fromTab(mTab1Copy);
+        Assert.assertNotEquals(tab1, tab1copy);
+        Assert.assertEquals(tab1.getId(), tab1copy.getId());
+    }
+
     @Test
     public void fromTab_cached_upgrade() {
         PseudoTab tab1 = PseudoTab.fromTabId(TAB1_ID);