Explicitly show and hide accessible rings rather than using offscreen coords.

chrome/browser/chromeos/ui/accessibility_focus_ring_controller.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/ui/accessibility_focus_ring_controller.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
@@ skipping 70 matching lines @@
 
 void AccessibilityFocusRingController::SetFocusRing(
     const std::vector<gfx::Rect>& rects,
     AccessibilityFocusRingController::FocusRingBehavior focus_ring_behavior) {
   focus_ring_behavior_ = focus_ring_behavior;
   OnLayerChange(&focus_animation_info_);
   focus_rects_ = rects;
   UpdateFocusRingsFromFocusRects();
 }
 
+void AccessibilityFocusRingController::HideFocusRing() {
+  focus_rects_.clear();
+  UpdateFocusRingsFromFocusRects();
+}
+
 void AccessibilityFocusRingController::UpdateFocusRingsFromFocusRects() {
   previous_focus_rings_.swap(focus_rings_);
   focus_rings_.clear();
   RectsToRings(focus_rects_, &focus_rings_);
   focus_layers_.resize(focus_rings_.size());
   if (focus_rings_.empty())
     return;
 
   for (size_t i = 0; i < focus_rings_.size(); ++i) {
     if (!focus_layers_[i])
@@ skipping 25 matching lines @@
   cursor_location_ = location;
   if (!cursor_layer_) {
     cursor_layer_.reset(new AccessibilityCursorRingLayer(
         this, kCursorRingColorRed, kCursorRingColorGreen,
         kCursorRingColorBlue));
   }
   cursor_layer_->Set(location);
   OnLayerChange(&cursor_animation_info_);
 }
 
+void AccessibilityFocusRingController::HideCursorRing() {
+  cursor_layer_.reset();
+}
+
 void AccessibilityFocusRingController::SetCaretRing(
     const gfx::Point& location) {
   caret_location_ = location;
 
   if (!caret_layer_) {
     caret_layer_.reset(new AccessibilityCursorRingLayer(
         this, kCaretRingColorRed, kCaretRingColorGreen, kCaretRingColorBlue));
   }
 
   caret_layer_->Set(location);
   OnLayerChange(&caret_animation_info_);
 }
 
+void AccessibilityFocusRingController::HideCaretRing() {
+  caret_layer_.reset();
+}
+
 void AccessibilityFocusRingController::SetNoFadeForTesting() {
   focus_animation_info_.fade_in_time = base::TimeDelta();
   focus_animation_info_.fade_out_time = base::TimeDelta::FromHours(1);
   cursor_animation_info_.fade_in_time = base::TimeDelta();
   cursor_animation_info_.fade_out_time = base::TimeDelta::FromHours(1);
   caret_animation_info_.fade_in_time = base::TimeDelta();
   caret_animation_info_.fade_out_time = base::TimeDelta::FromHours(1);
 }
 
 void AccessibilityFocusRingController::RectsToRings(
@@ skipping 294 matching lines @@
 
   ComputeOpacity(&caret_animation_info_, timestamp);
   if (caret_animation_info_.opacity == 0.0) {
     caret_layer_.reset();
     return;
   }
   caret_layer_->SetOpacity(caret_animation_info_.opacity);
 }
 
 }  // namespace chromeos