Add tests for DocumentModeAssassin#isOptedOutOfDocumentMode()

BUG=646146

Review-Url: https://codereview.chromium.org/2337143004
Cr-Commit-Position: refs/heads/master@{#418954}

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

@@ -106,16 +106,16 @@ public class DocumentModeAssassin {
     private static final int TAB_MODEL_INDEX = 0;
 
     /** SharedPreference values to determine whether user had document mode turned on. */
-    private static final String OPT_OUT_STATE = "opt_out_state";
+    static final String OPT_OUT_STATE = "opt_out_state";
     private static final int OPT_IN_TO_DOCUMENT_MODE = 0;
     private static final int OPT_OUT_STATE_UNSET = -1;
-    private static final int OPTED_OUT_OF_DOCUMENT_MODE = 2;
+    static final int OPTED_OUT_OF_DOCUMENT_MODE = 2;
 
     /**
      * Preference that denotes that Chrome has attempted to migrate from tabbed mode to document
      * mode. Indicates that the user may be in document mode.
      */
-    public static final String MIGRATION_ON_UPGRADE_ATTEMPTED = "migration_on_upgrade_attempted";
+    static final String MIGRATION_ON_UPGRADE_ATTEMPTED = "migration_on_upgrade_attempted";
 
     /** Creates and holds the Singleton. */
     private static class LazyHolder {

chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/DocumentModeAssassinTest.java

@@ -612,6 +612,45 @@ public class DocumentModeAssassinTest extends NativeLibraryTestBase {
         assertFalse(prefs.contains(keyToBeDeleted));
     }
 
+    @SmallTest
+    public void testIsOptedOutOfDocumentModeMigration() throws Exception {
+        TabPersistentStore.setBaseStateDirectoryForTests(mTabbedModeDirectory.getBaseDirectory());
+        SharedPreferences.Editor sharedPreferencesEditor =
+                ContextUtils.getAppSharedPreferences().edit();
+
+        // If no preferences for document mode are set, the user is not in document mode.
+        sharedPreferencesEditor.remove(DocumentModeAssassin.MIGRATION_ON_UPGRADE_ATTEMPTED);
+        sharedPreferencesEditor.remove(DocumentModeAssassin.OPT_OUT_STATE);
+        sharedPreferencesEditor.apply();
+        assertTrue(DocumentModeAssassin.isOptedOutOfDocumentMode());
+
+        // If the preference for opting out of document mode is set, the user is not in document
+        // mode.
+        sharedPreferencesEditor.remove(DocumentModeAssassin.MIGRATION_ON_UPGRADE_ATTEMPTED);
+        sharedPreferencesEditor.putInt(DocumentModeAssassin.OPT_OUT_STATE,
+                DocumentModeAssassin.OPTED_OUT_OF_DOCUMENT_MODE);
+        sharedPreferencesEditor.apply();
+        assertTrue(DocumentModeAssassin.isOptedOutOfDocumentMode());
+
+        // If the user has been migrated into document mode and no preference has been set for
+        // OPT_OUT_STATE, the user should still be in document mode.
+        sharedPreferencesEditor.putBoolean(DocumentModeAssassin.MIGRATION_ON_UPGRADE_ATTEMPTED,
+                true);
+        sharedPreferencesEditor.remove(DocumentModeAssassin.OPT_OUT_STATE);
+        sharedPreferencesEditor.apply();
+        assertFalse(DocumentModeAssassin.isOptedOutOfDocumentMode());
+
+        // If the user has been migrated into document mode and no preference has been set for
+        // OPT_OUT_STATE, but a "new" tabbed mode metadata file exists, migration has already been
+        // attempted or incorrectly skipped. The user is not in document mode.
+        sharedPreferencesEditor.putBoolean(DocumentModeAssassin.MIGRATION_ON_UPGRADE_ATTEMPTED,
+                true);
+        sharedPreferencesEditor.remove(DocumentModeAssassin.OPT_OUT_STATE);
+        sharedPreferencesEditor.apply();
+        mTabbedModeDirectory.writeTabModelFiles(TestTabModelDirectory.TAB_MODEL_METADATA_V5, false);
+        assertTrue(DocumentModeAssassin.isOptedOutOfDocumentMode());
+    }
+
     /** Creates a DocumentModeAssassin with all of its calls pointing at our mocked classes.
      * @param isMigrationNecessary TODO(dfalcantara):*/
     private DocumentModeAssassinForTesting createAssassinForTesting(