Add Chrome OS accessibility histograms.

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/metrics/histogram.h"
 #include "base/timer.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 62 matching lines @@
 
 void BrowserAccessibilityStateImpl::OnAccessibilityEnabledManually() {
   // We may want to do something different with this later.
   SetAccessibilityMode(AccessibilityModeComplete);
 }
 
 bool BrowserAccessibilityStateImpl::IsAccessibleBrowser() {
   return (accessibility_mode_ == AccessibilityModeComplete);
 }
 
+void BrowserAccessibilityStateImpl::AddHistogramCallback(
+    base::Closure callback) {
+  histogram_callbacks_.push_back(callback);
+}
+
 void BrowserAccessibilityStateImpl::UpdateHistogram() {
   UpdatePlatformSpecificHistograms();
 
+  for (size_t i = 0; i < histogram_callbacks_.size(); ++i)
+    histogram_callbacks_[i].Run();
+
   UMA_HISTOGRAM_BOOLEAN("Accessibility.State", IsAccessibleBrowser());
   UMA_HISTOGRAM_BOOLEAN("Accessibility.InvertedColors",
                         gfx::IsInvertedColorScheme());
   UMA_HISTOGRAM_BOOLEAN("Accessibility.ManuallyEnabled",
                         CommandLine::ForCurrentProcess()->HasSwitch(
                             switches::kForceRendererAccessibility));
 }
 
 #if !defined(OS_WIN)
 void BrowserAccessibilityStateImpl::UpdatePlatformSpecificHistograms() {
 }
 #endif
 
 AccessibilityMode BrowserAccessibilityStateImpl::GetAccessibilityMode() {
   return accessibility_mode_;
 }
 
 void BrowserAccessibilityStateImpl::SetAccessibilityMode(
     AccessibilityMode mode) {
   accessibility_mode_ = mode;
 }
 
 }  // namespace content