Fix crash when AccessibilityManager called when profile is nullptr

chrome/browser/chromeos/accessibility/accessibility_manager.cc

Index: chrome/browser/chromeos/accessibility/accessibility_manager.cc
diff --git a/chrome/browser/chromeos/accessibility/accessibility_manager.cc b/chrome/browser/chromeos/accessibility/accessibility_manager.cc
index e7af4a292fe226a5948afd3302adcfd602b4164f..5b840c778f69f765d7aee1901412fe79be92e204 100644
--- a/chrome/browser/chromeos/accessibility/accessibility_manager.cc
+++ b/chrome/browser/chromeos/accessibility/accessibility_manager.cc
@@ -598,6 +598,9 @@ bool AccessibilityManager::PlayEarcon(int sound_key, PlaySoundOption option) {
 }
 
 void AccessibilityManager::OnTwoFingerTouchStart() {
+  if (!profile())

[oshima, 2017/05/02 01:45:20]

optional: just noticed that all other places are using profile_. I'm fine as is
though.

+    return;
+
   extensions::EventRouter* event_router =
       extensions::EventRouter::Get(profile());
   CHECK(event_router);
@@ -611,6 +614,9 @@ void AccessibilityManager::OnTwoFingerTouchStart() {
 }
 
 void AccessibilityManager::OnTwoFingerTouchStop() {
+  if (!profile())
+    return;
+
   extensions::EventRouter* event_router =
       extensions::EventRouter::Get(profile());
   CHECK(event_router);