Add an experimental keyboard lock, where Esc must be held to exit.

chrome/browser/ui/exclusive_access/exclusive_access_manager.cc

Index: chrome/browser/ui/exclusive_access/exclusive_access_manager.cc
diff --git a/chrome/browser/ui/exclusive_access/exclusive_access_manager.cc b/chrome/browser/ui/exclusive_access/exclusive_access_manager.cc
index 666d11e6970660990014e60c2a88d65f567d018b..3492dc448f0195afd22ddf435be1e4ec709c5552 100644
--- a/chrome/browser/ui/exclusive_access/exclusive_access_manager.cc
+++ b/chrome/browser/ui/exclusive_access/exclusive_access_manager.cc
@@ -19,6 +19,15 @@
 
 using content::WebContents;
 
+namespace {
+
+// Time in milliseconds to hold the Esc key in order to exit full screen.
+// TODO(dominickn) refactor the way timings/input handling works so this
+// constant doesn't have to be in this file.
+const int kHoldEscapeTimeMs = 1500;
+
+}
+
 ExclusiveAccessManager::ExclusiveAccessManager(
     ExclusiveAccessContext* exclusive_access_context)
     : exclusive_access_context_(exclusive_access_context),
@@ -58,6 +67,8 @@ ExclusiveAccessManager::GetExclusiveAccessExitBubbleType() const {
   if (fullscreen_controller_.IsUserAcceptedFullscreen()) {
     if (fullscreen_controller_.IsPrivilegedFullscreenForTab())
       return EXCLUSIVE_ACCESS_BUBBLE_TYPE_NONE;
+    if (IsExperimentalKeyboardLockUIEnabled())
+      return EXCLUSIVE_ACCESS_BUBBLE_TYPE_KEYBOARD_LOCK_EXIT_INSTRUCTION;
     if (mouse_lock_controller_.IsMouseLocked())
       return EXCLUSIVE_ACCESS_BUBBLE_TYPE_FULLSCREEN_MOUSELOCK_EXIT_INSTRUCTION;
     if (mouse_lock_controller_.IsMouseLockRequested())
@@ -91,6 +102,11 @@ GURL ExclusiveAccessManager::GetExclusiveAccessBubbleURL() const {
 }
 
 // static
+bool ExclusiveAccessManager::IsExperimentalKeyboardLockUIEnabled() {
+  return base::FeatureList::IsEnabled(features::kExperimentalKeyboardLockUI);
+}
+
+// static
 bool ExclusiveAccessManager::IsSimplifiedFullscreenUIEnabled() {
   return base::FeatureList::IsEnabled(features::kSimplifiedFullscreenUI);
 }
@@ -117,6 +133,27 @@ bool ExclusiveAccessManager::HandleUserKeyPress(
     return false;
   }
 
+  if (IsExperimentalKeyboardLockUIEnabled()) {
+    if (event.type == content::NativeWebKeyboardEvent::KeyUp &&
+        hold_timer_.IsRunning()) {
+      // Seeing a key up event on Esc with the hold timer running cancels the
+      // timer and doesn't exit. This means the user pressed Esc, but not long
+      // enough to trigger an exit
+      hold_timer_.Stop();
+    } else if (event.type == content::NativeWebKeyboardEvent::RawKeyDown &&
+              !hold_timer_.IsRunning()) {
+      // Seeing a key down event on Esc when the hold timer is stopped starts
+      // the timer. When the timer reaches 0, the callback will trigger an exit
+      // from fullscreen/mouselock.
+      hold_timer_.Start(
+          FROM_HERE, base::TimeDelta::FromMilliseconds(kHoldEscapeTimeMs),
+          base::Bind(&ExclusiveAccessManager::HandleUserHeldEscape,
+                     base::Unretained(this)));
+    }
+    // We never handle the keyboard event.
+    return false;
+  }
+
   bool handled = false;
   handled = fullscreen_controller_.HandleUserPressedEscape();
   handled |= mouse_lock_controller_.HandleUserPressedEscape();
@@ -159,6 +196,7 @@ void ExclusiveAccessManager::RecordBubbleReshownUMA(
       break;
     case EXCLUSIVE_ACCESS_BUBBLE_TYPE_FULLSCREEN_BUTTONS:
     case EXCLUSIVE_ACCESS_BUBBLE_TYPE_FULLSCREEN_EXIT_INSTRUCTION:
+    case EXCLUSIVE_ACCESS_BUBBLE_TYPE_KEYBOARD_LOCK_EXIT_INSTRUCTION:
     case EXCLUSIVE_ACCESS_BUBBLE_TYPE_BROWSER_FULLSCREEN_EXIT_INSTRUCTION:
     case EXCLUSIVE_ACCESS_BUBBLE_TYPE_EXTENSION_FULLSCREEN_EXIT_INSTRUCTION:
       // Only fullscreen in effect.
@@ -181,3 +219,8 @@ void ExclusiveAccessManager::RecordBubbleReshownUMA(
   if (mouselock)
     mouse_lock_controller_.RecordBubbleReshownUMA();
 }
+
+void ExclusiveAccessManager::HandleUserHeldEscape() {
+  fullscreen_controller_.HandleUserPressedEscape();
+  mouse_lock_controller_.HandleUserPressedEscape();
+}