Fix ChromeVox's detection of whether the current document has focus.

chrome/browser/resources/chromeos/chromevox/common/chromevox.js

Index: chrome/browser/resources/chromeos/chromevox/common/chromevox.js
diff --git a/chrome/browser/resources/chromeos/chromevox/common/chromevox.js b/chrome/browser/resources/chromeos/chromevox/common/chromevox.js
index 04c0bd36673cc89711223f085dbb9f4a50e18593..db20382a06ab570fa42197ec1f4209f701e5b685 100644
--- a/chrome/browser/resources/chromeos/chromevox/common/chromevox.js
+++ b/chrome/browser/resources/chromeos/chromevox/common/chromevox.js
@@ -275,3 +275,20 @@ function $(id) {
  * @param {Array} tabs
  */
 cvox.ChromeVox.injectChromeVoxIntoTabs = function(tabs) {};
+
+/**
+ * Returns whether the document has focus, taking into account whether
+ * it's hidden and also that if an iframe or webview element has focus,
+ * the focus is really inside that frame and not in this document.
+ * @return {boolean} True if the document has focus.
+ */
+cvox.ChromeVox.documentHasFocus = function() {
+  if (!document.hasFocus() || document.hidden) {
+    return false;
+  }
+  if (document.activeElement.tagName == 'IFRAME' ||
+      document.activeElement.tagName == 'WEBVIEW') {
+    return false;
+  }
+  return true;
+};