Add an accessibility mode for editable text fields only.

content/browser/accessibility/browser_accessibility_state_impl.cc

 // Copyright (c) 2012 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 "content/browser/accessibility/browser_accessibility_state_impl.h"
 
+#include "base/command_line.h"
 #include "base/memory/singleton.h"
 #include "base/metrics/histogram.h"
 #include "base/timer.h"
+#include "content/public/common/content_switches.h"
 #include "ui/gfx/sys_color_change_listener.h"
 
 // Update the accessibility histogram 45 seconds after initialization.
 static const int kAccessibilityHistogramDelaySecs = 45;
 
 // static
 BrowserAccessibilityState* BrowserAccessibilityState::GetInstance() {
   return BrowserAccessibilityStateImpl::GetInstance();
 }
 
 // static
 BrowserAccessibilityStateImpl* BrowserAccessibilityStateImpl::GetInstance() {
   return Singleton<BrowserAccessibilityStateImpl>::get();
 }
 
 BrowserAccessibilityStateImpl::BrowserAccessibilityStateImpl()
     : BrowserAccessibilityState(),
       accessibility_enabled_(false) {
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kForceRendererAccessibility)) {
+    OnAccessibilityEnabledManually();
+  }
   update_histogram_timer_.Start(
       FROM_HERE,
       base::TimeDelta::FromSeconds(kAccessibilityHistogramDelaySecs),
       this,
       &BrowserAccessibilityStateImpl::UpdateHistogram);
 }
 
 BrowserAccessibilityStateImpl::~BrowserAccessibilityStateImpl() {
 }
 
 void BrowserAccessibilityStateImpl::OnScreenReaderDetected() {
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDisableRendererAccessibility)) {
+    return;
+  }
   accessibility_enabled_ = true;
 }
 
 void BrowserAccessibilityStateImpl::OnAccessibilityEnabledManually() {
   // We may want to do something different with this later.
   accessibility_enabled_ = true;
 }
 
 bool BrowserAccessibilityStateImpl::IsAccessibleBrowser() {
   return accessibility_enabled_;
 }
 
 void BrowserAccessibilityStateImpl::UpdateHistogram() {
   UMA_HISTOGRAM_ENUMERATION("Accessibility.State",
                             accessibility_enabled_ ? 1 : 0,
                             2);
   UMA_HISTOGRAM_ENUMERATION("Accessibility.InvertedColors",
                             gfx::IsInvertedColorScheme() ? 1 : 0,
                             2);
 }