Fixes Switch Access on profile change

SA should handle reload (pref didn't change, but the profile changed). Similar to STS and ChromeVox.

R=anastasi@google.com, dmazzoni@chromium.org

AX-Relnotes: n/a
Fixed: 1125211
Test: manual; on-device
Change-Id: I0ab62e970d2cf948512bf49947a48bd1d7aacda9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2398939Reviewed-by: Anastasia Helfinstein <anastasi@google.com>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: David Tseng <dtseng@chromium.org>
Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#804969}

chrome/browser/chromeos/accessibility/accessibility_manager.cc

@@ -900,6 +900,9 @@ void AccessibilityManager::OnSwitchAccessChanged() {
   const bool enabled = profile_->GetPrefs()->GetBoolean(
       ash::prefs::kAccessibilitySwitchAccessEnabled);
 
+  if (enabled)
+    switch_access_loader_->SetProfile(profile_, base::Closure());
+
   if (switch_access_enabled_ == enabled)
     return;
   switch_access_enabled_ = enabled;