Add kAccessibilityFocusFallsbackToWidget property

chrome/browser/chromeos/accessibility/spoken_feedback_browsertest.cc

Index: chrome/browser/chromeos/accessibility/spoken_feedback_browsertest.cc
diff --git a/chrome/browser/chromeos/accessibility/spoken_feedback_browsertest.cc b/chrome/browser/chromeos/accessibility/spoken_feedback_browsertest.cc
index d1f2c1f760c70454ac7d06bc8d0b7a510fc6bd55..dc8f0c162cc93bdd5ba9cc5c019166d99ad84bb5 100644
--- a/chrome/browser/chromeos/accessibility/spoken_feedback_browsertest.cc
+++ b/chrome/browser/chromeos/accessibility/spoken_feedback_browsertest.cc
@@ -500,6 +500,7 @@ IN_PROC_BROWSER_TEST_P(SpokenFeedbackTest, OverviewMode) {
       break;
   }
 
+  EXPECT_EQ(", window", speech_monitor_.GetNextUtterance());

[dmazzoni, 2016/11/29 17:50:17]

Instead of adding this expectation, which may just
break again soon, change the next line to a loop
that loops until "Entered window overview mode"
is matched.

[yawano, 2016/11/30 10:55:54]

Done.

   EXPECT_EQ("Entered window overview mode", speech_monitor_.GetNextUtterance());
 
   SendKeyPress(ui::VKEY_TAB);
@@ -534,8 +535,8 @@ IN_PROC_BROWSER_TEST_P(SpokenFeedbackTest, MAYBE_ChromeVoxShiftSearch) {
 
   // Press Search+/ to enter ChromeVox's "find in page".
   SendKeyPressWithSearch(ui::VKEY_OEM_2);
-  EXPECT_EQ(", window", speech_monitor_.GetNextUtterance());
   EXPECT_EQ("webView", speech_monitor_.GetNextUtterance());

[dmazzoni, 2016/11/29 17:50:17]

Same, let's get rid of this expectation and just loop
until "Find in page" is heard

[yawano, 2016/11/30 10:55:54]

Done.

+  EXPECT_EQ(", window", speech_monitor_.GetNextUtterance());
   EXPECT_EQ("Find in page.", speech_monitor_.GetNextUtterance());
 }