Toggle spoken feedback if two fingers are held down.

ash/ash_touch_exploration_manager_chromeos.cc

Index: ash/ash_touch_exploration_manager_chromeos.cc
diff --git a/ash/ash_touch_exploration_manager_chromeos.cc b/ash/ash_touch_exploration_manager_chromeos.cc
index 8eda21eebdac5d43bafa95e6e7d0744f40322b6b..363f6df647f8d8903c4cc9c8ddafa4fca6cbfe2a 100644
--- a/ash/ash_touch_exploration_manager_chromeos.cc
+++ b/ash/ash_touch_exploration_manager_chromeos.cc
@@ -102,6 +102,17 @@ void AshTouchExplorationManager::OnDisplayMetricsChanged(
     UpdateTouchExplorationState();
 }
 
+void AshTouchExplorationManager::PlaySpokenFeedbackToggleCountdown(
+    int tick_count) {
+  WmShell::Get()->accessibility_delegate()->PlaySpokenFeedbackToggleCountdown(
+      tick_count);
+}
+
+void AshTouchExplorationManager::ToggleSpokenFeedback() {
+  WmShell::Get()->accessibility_delegate()->ToggleSpokenFeedback(
+      ash::A11Y_NOTIFICATION_SHOW);
+}
+
 void AshTouchExplorationManager::OnWindowActivated(
     aura::client::ActivationChangeObserver::ActivationReason reason,
     aura::Window* gained_active,
@@ -129,11 +140,18 @@ void AshTouchExplorationManager::UpdateTouchExplorationState() {
   const bool spoken_feedback_enabled =
       WmShell::Get()->accessibility_delegate()->IsSpokenFeedbackEnabled();
 
+  if (!touch_accessibility_enabler_) {
+    // Always enable gesture to toggle spoken feedback.
+    touch_accessibility_enabler_.reset(new ui::TouchAccessibilityEnabler(
+        root_window_controller_->GetRootWindow(), this));
+  }
+
   if (spoken_feedback_enabled) {
     if (!touch_exploration_controller_.get()) {
       touch_exploration_controller_ =
           base::MakeUnique<ui::TouchExplorationController>(
-              root_window_controller_->GetRootWindow(), this);
+              root_window_controller_->GetRootWindow(), this,
+              touch_accessibility_enabler_.get());
     }
     if (pass_through_surface) {
       const gfx::Rect& work_area =