Reland: Make the check for compat mode explicit.

chrome/browser/resources/chromeos/chromevox/cvox2/background/background_test.extjs

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Include test fixture.
 GEN_INCLUDE(['../../testing/chromevox_next_e2e_test_base.js',
              '../../testing/assert_additions.js']);
 
 GEN_INCLUDE(['../../testing/mock_feedback.js']);
 
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           .call(off)
           .call(focusThen.bind(this, rootNode.find({ role: 'link' }), on))
           .call(focusThen.bind(this, rootNode.find({ role: 'textField' })))
           .expectNextSpeechUtteranceIsNot('a')
           .expectSpeech('Edit text');
 
       mockFeedback.replay();
     }
   );
 });
+
+TEST_F('BackgroundTest', 'ModeSwitching', function() {
+  this.runWithLoadedTree('<button></button>', function(root) {
+    // Tests default to force next mode.
+    assertEquals('force_next', global.backgroundObj.mode);
+
+    // Force next mode stays set regardless of where the range lands.
+    global.backgroundObj.refreshMode('http://google.com');
+    assertEquals('force_next', global.backgroundObj.mode);
+    // Empty urls occur before document load or when root is desktop.
+    global.backgroundObj.refreshMode('');
+    assertEquals('force_next', global.backgroundObj.mode);
+
+    // Verify compat -> classic switching.
+    global.backgroundObj.setMode('compat');
+    global.backgroundObj.refreshMode('http://google.com');
+    assertEquals('classic', global.backgroundObj.mode);
+
+    // Ensure we switch to compat if our current range has focused
+    // state set and is not in web content.
+    assertTrue(root.parent.state.focused);
+    global.backgroundObj.setCurrentRange(cursors.Range.fromNode(root.parent));
+    global.backgroundObj.refreshMode('');
+    assertEquals('compat', global.backgroundObj.mode);
+
+    // And back to classic.
+    global.backgroundObj.setCurrentRange(cursors.Range.fromNode(root));
+    global.backgroundObj.refreshMode('');
+    assertEquals('classic', global.backgroundObj.mode);
+
+    // Now, try refreshing mode (which we call after tab switching) with a range
+    // that's not actually focused.
+    assertEquals(undefined, root.parent.parent.state.focused);
+    global.backgroundObj.setCurrentRange(cursors.Range.fromNode(root.parent.parent));
+    global.backgroundObj.refreshMode('');
+    assertEquals('classic', global.backgroundObj.mode);
+  }.bind(this));
+});