Utilize focus recovery in more code paths

1. alt+left/right

Chrome only fires focus events in this case. This change tries to
recover focus whenever a focus event gets fired on a root web area. The
challenge here is the root node gets re-used. Explicit tracking of the
docurl gets introduced as a result.

Forum discussion:
https://groups.google.com/forum/#!topic/axs-chrome-discuss/u9gcqZxDISM

2. toggle on ChromeVox

In this case, ChromeVox tries to always recover focus. Detected by
checking there is no |currentRange|.

3. ctrl+r

In this case, ChromeVox receives a load complete. Only recover if the
|focus| is not already inside of the page (i.e. |focus| is the top level
root).

restores its range appropriately.

Test: exercise each of the above examples; verify that ChromeVox
Bug: 
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I6e427105555b2663dca1100a02b8eb6b00cdc08a
Reviewed-on: https://chromium-review.googlesource.com/806759
Commit-Queue: David Tseng <dtseng@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521909}

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

@@ -324,7 +324,7 @@ AutomationPredicate.root = function(node) {
         // to be crossed when performing traversals up the ancestry chain.
         return false;
       }
-      return !node.parent ||
+      return !node.parent || !node.parent.root ||
           (node.parent.root.role == Role.DESKTOP &&
            node.parent.role == Role.WEB_VIEW);
     default:

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

@@ -377,12 +377,12 @@ Background.prototype = {
       var start = this.currentRange_.start.node;
       start.makeVisible();
 
-      var root = start.root;
+      var root = AutomationUtil.getTopLevelRoot(start);
       if (!root || root.role == RoleType.DESKTOP)
         return;
 
       var position = {};
-      var loc = start.location;
+      var loc = start.unclippedLocation;
       position.x = loc.left + loc.width / 2;
       position.y = loc.top + loc.height / 2;
       var url = root.docUrl;

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

@@ -525,13 +525,13 @@ TEST_F('BackgroundTest', 'ModeSwitching', function() {
     fakeWebRoot.parent = fakeDesktop;
     fakeWebRoot.role = RoleType.ROOT_WEB_AREA;
     fakeWebRoot.makeVisible = function() {};
-    fakeWebRoot.location = {left: 1, top: 1, width: 1, height: 1};
+    fakeWebRoot.unclippedLocation = {left: 1, top: 1, width: 1, height: 1};
     var fakeSubRoot = {};
     fakeSubRoot.root = fakeSubRoot;
     fakeSubRoot.parent = fakeWebRoot;
     fakeSubRoot.role = RoleType.ROOT_WEB_AREA;
     fakeSubRoot.makeVisible = function() {};
-    fakeSubRoot.location = {left: 1, top: 1, width: 1, height: 1};
+    fakeSubRoot.unclippedLocation = {left: 1, top: 1, width: 1, height: 1};
     var bk = ChromeVoxState.instance;
 
     // Tests default to force next mode.

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

@@ -47,6 +47,9 @@ DesktopAutomationHandler = function(node) {
   /** @private {AutomationNode} */
   this.lastValueTarget_ = null;
 
+  /** @private {string} */
+  this.lastRootUrl_ = '';
+
   this.addListener_(
       EventType.ACTIVEDESCENDANTCHANGED, this.onActiveDescendantChanged);
   this.addListener_(EventType.ALERT, this.onAlert);
@@ -296,6 +299,11 @@ DesktopAutomationHandler.prototype = {
    * @param {!AutomationEvent} evt
    */
   onFocus: function(evt) {
+    if (evt.target.role == RoleType.ROOT_WEB_AREA) {
+      this.maybeRecoverFocusAndOutput_(evt);
+      return;
+    }
+
     // Invalidate any previous editable text handler state.
     if (!this.createTextEditHandlerIfNeeded_(evt.target))
       this.textEditHandler_ = null;
@@ -361,33 +369,7 @@ DesktopAutomationHandler.prototype = {
         return;
       }
 
-      // If initial focus was already placed on this page (e.g. if a user starts
-      // tabbing before load complete), then don't move ChromeVox's position on
-      // the page.
-      if (ChromeVoxState.instance.currentRange &&
-          ChromeVoxState.instance.currentRange.start.node.root == focus.root)
-        return;
-
-      var o = new Output();
-      if (focus.role == RoleType.ROOT_WEB_AREA) {
-        // Restore to previous position.
-        var url = focus.docUrl;
-        url = url.substring(0, url.indexOf('#')) || url;
-        var pos = cvox.ChromeVox.position[url];
-        if (pos) {
-          focus = AutomationUtil.hitTest(focus.root, pos) || focus;
-          if (focus != focus.root)
-            o.format('$name', focus.root);
-        }
-      }
-      ChromeVoxState.instance.setCurrentRange(cursors.Range.fromNode(focus));
-      if (!this.shouldOutput_(evt))
-        return;
-
-      Output.forceModeForNextSpeechUtterance(cvox.QueueMode.FLUSH);
-      o.withRichSpeechAndBraille(
-           ChromeVoxState.instance.currentRange, null, evt.type)
-          .go();
+      this.maybeRecoverFocusAndOutput_(evt);
     }.bind(this));
   },
 
@@ -602,6 +584,60 @@ DesktopAutomationHandler.prototype = {
     return evt.target.root.role == RoleType.DESKTOP ||
         (mode == ChromeVoxMode.NEXT || mode == ChromeVoxMode.FORCE_NEXT ||
          mode == ChromeVoxMode.CLASSIC_COMPAT);
+  },
+
+  /**
+   * @param {AutomationEvent} evt
+   * @private
+   */
+  maybeRecoverFocusAndOutput_: function(evt) {
+    chrome.automation.getFocus(function(focus) {
+      var focusedRoot = AutomationUtil.getTopLevelRoot(focus);
+      if (!focusedRoot)
+        return;
+
+      var curRoot;
+      if (ChromeVoxState.instance.currentRange) {
+        curRoot = AutomationUtil.getTopLevelRoot(
+            ChromeVoxState.instance.currentRange.start.node);
+      }
+
+      // If initial focus was already placed inside this page (e.g. if a user
+      // starts tabbing before load complete), then don't move ChromeVox's
+      // position on the page.
+      if (curRoot && focusedRoot == curRoot &&
+          this.lastRootUrl_ == focusedRoot.docUrl && focus != focusedRoot)
+        return;
+
+      this.lastRootUrl_ = focusedRoot.docUrl || '';
+      var o = new Output();
+      // Restore to previous position.
+      var url = focusedRoot.docUrl;
+      url = url.substring(0, url.indexOf('#')) || url;
+      var pos = cvox.ChromeVox.position[url];
+      if (pos) {
+        focus = AutomationUtil.hitTest(focusedRoot, pos) || focus;
+        if (focus != focusedRoot)
+          o.format('$name', focusedRoot);
+      } else {
+        // This catches initial focus (i.e. on startup).
+        if (!curRoot && focus != focusedRoot)
+          o.format('$name', focusedRoot);
+      }
+
+      if (ChromeVoxState.instance.currentRange &&
+          focus == ChromeVoxState.instance.currentRange.start.node)
+        return;
+
+      ChromeVoxState.instance.setCurrentRange(cursors.Range.fromNode(focus));
+      if (!this.shouldOutput_(evt))
+        return;
+
+      Output.forceModeForNextSpeechUtterance(cvox.QueueMode.FLUSH);
+      o.withRichSpeechAndBraille(
+           ChromeVoxState.instance.currentRange, null, evt.type)
+          .go();
+    }.bind(this));
   }
 };