Add the partial screen magnifier to Chrome OS.

chrome/browser/chromeos/accessibility/accessibility_util.cc

Index: chrome/browser/chromeos/accessibility/accessibility_util.cc
diff --git a/chrome/browser/chromeos/accessibility/accessibility_util.cc b/chrome/browser/chromeos/accessibility/accessibility_util.cc
index a3111806e5ebc1b6b466bb26435205c3753a605f..99b75521a84a33e479c343f8599463057f71eee3 100644
--- a/chrome/browser/chromeos/accessibility/accessibility_util.cc
+++ b/chrome/browser/chromeos/accessibility/accessibility_util.cc
@@ -8,6 +8,7 @@
 
 #include "ash/high_contrast/high_contrast_controller.h"
 #include "ash/magnifier/magnification_controller.h"
+#include "ash/magnifier/partial_magnification_controller.h"
 #include "ash/shell.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ -175,13 +176,19 @@ void EnableHighContrast(bool enabled) {
 #endif
 }
 
-void EnableScreenMagnifier(bool enabled) {
+void SetScreenMagnifier(ScreenMagnifierType type) {
   PrefService* pref_service = g_browser_process->local_state();
-  pref_service->SetBoolean(prefs::kScreenMagnifierEnabled, enabled);
+  pref_service->SetBoolean(prefs::kScreenMagnifierEnabled,
+                           type == MagnifierFull);
+  pref_service->SetBoolean(prefs::kPartialScreenMagnifierEnabled,
+                           type == MagnifierPartial);
   pref_service->CommitPendingWrite();
 
 #if defined(USE_ASH)
-  ash::Shell::GetInstance()->magnification_controller()->SetEnabled(enabled);
+  ash::Shell::GetInstance()->magnification_controller()->SetEnabled(
+      type == MagnifierFull);
+  ash::Shell::GetInstance()->partial_magnification_controller()->SetEnabled(
+      type == MagnifierPartial);
 #endif
 }
 
@@ -234,13 +241,20 @@ bool IsHighContrastEnabled() {
   return high_contrast_enabled;
 }
 
-bool IsScreenMagnifierEnabled() {
-  if (!g_browser_process) {
-    return false;
-  }
+ScreenMagnifierType GetScreenMagnifierType() {
+  if (!g_browser_process)
+    return MagnifierNone;
+
   PrefService* prefs = g_browser_process->local_state();
-  bool enabled = prefs && prefs->GetBoolean(prefs::kScreenMagnifierEnabled);
-  return enabled;
+  if (!prefs)
+    return MagnifierNone;
+
+  if (prefs->GetBoolean(prefs::kScreenMagnifierEnabled))
+    return MagnifierFull;
+  else if (prefs->GetBoolean(prefs::kPartialScreenMagnifierEnabled))
+    return MagnifierPartial;
+  else
+    return MagnifierNone;
 }
 
 void MaybeSpeak(const std::string& utterance) {