Keep track of accessibility focus across windows.

chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js

Index: chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js
diff --git a/chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js b/chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js
index bea4f4861f4d40f687adb3beedb014c5bde4c56c..07c903259303f39e870ad465511443265282568c 100644
--- a/chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js
+++ b/chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js
@@ -126,6 +126,10 @@ Background = function() {
 
   if (!chrome.accessibilityPrivate.setKeyboardListener)
     chrome.accessibilityPrivate.setKeyboardListener = function() {};
+
+  var focus = chrome.automation.getFocus();
+  if (focus)
+    this.setCurrentRange(cursors.Range.fromNode(focus));
 };
 
 Background.prototype = {
@@ -190,6 +194,21 @@ Background.prototype = {
       cvox.ChromeVox.earcons.cancelEarcon(cvox.Earcon.PAGE_START_LOADING);
     }
 
+    // If switching to Classic from any automation-API-based mode,
+    // clear the focus ring.
+    if (mode === ChromeVoxMode.CLASSIC && mode != this.mode_) {
+      if (cvox.ChromeVox.isChromeOS)
+        chrome.accessibilityPrivate.setFocusRing([]);
+    }
+
+    // If switching away from Classic to any automation-API-based mode,
+    // update the range based on what's focused.
+    if (this.mode_ === ChromeVoxMode.CLASSIC && mode != this.mode_) {
+      var focus = chrome.automation.getFocus();
+      if (focus)
+        this.setCurrentRange(cursors.Range.fromNode(focus));
+    }
+
     this.mode_ = mode;
   },
 
@@ -465,6 +484,12 @@ Background.prototype = {
         // Leaving unlocalized as 'next' isn't an official name.
         cvox.ChromeVox.tts.speak(isClassic ?
             'classic' : 'next', cvox.QueueMode.FLUSH, {doNotInterrupt: true});
+
+        // If the new mode is Classic, return now so we don't announce

[David Tseng, 2016/01/28 02:00:56]

Maybe add something to queue the next utterance?

[dmazzoni, 2016/01/30 00:02:41]

For Classic? Did you have something specific in mind? I'm not sure how to do
this and I'd rather not spend time on improving Classic.

Right now the experience is that switching to Next says "Next", followed by
whatever has focus, and switching to Classic just says "Classic" and doesn't
currently announce anything.

+        // anything more.
+        if (newMode == ChromeVoxMode.CLASSIC)
+          return false;
+

[David Tseng, 2016/01/28 02:00:56]

nit: extra line

[dmazzoni, 2016/01/30 00:02:41]

Done.

         break;
       case 'toggleStickyMode':
         cvox.ChromeVoxBackground.setPref('sticky',