diff --git a/ash/ash_switches.cc b/ash/ash_switches.cc
index 7f052dcd2d1ec1..4ec2e792470641 100644
--- a/ash/ash_switches.cc
+++ b/ash/ash_switches.cc
@@ -55,6 +55,9 @@ const char kAshEnableFullscreenAppList[] = "ash-enable-fullscreen-app-list";
 const char kAshEnableMagnifierKeyScroller[] =
     "ash-enable-magnifier-key-scroller";
 
+// Enables unified desktop mode.
+const char kAshEnableUnifiedDesktop[] = "ash-enable-unified-desktop";
+
 #endif
 
 // Enables mirrored screen.
@@ -131,9 +134,7 @@ bool ConstrainPointerToRoot() {
              kAshConstrainPointerToRoot);
 }
 
-// Enables unified desktop mode.
 bool UnifiedDesktopEnabled() {
-  const char kAshEnableUnifiedDesktop[] = "ash-enable-unified-desktop";
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
       kAshEnableUnifiedDesktop);
 }
diff --git a/ash/ash_switches.h b/ash/ash_switches.h
index 171272fe72de9d..2c0baaea1bc4bf 100644
--- a/ash/ash_switches.h
+++ b/ash/ash_switches.h
@@ -29,6 +29,7 @@ ASH_EXPORT extern const char kAshDisableTouchExplorationMode[];
 #if defined(OS_CHROMEOS)
 ASH_EXPORT extern const char kAshEnableFullscreenAppList[];
 ASH_EXPORT extern const char kAshEnableMagnifierKeyScroller[];
+ASH_EXPORT extern const char kAshEnableUnifiedDesktop[];
 #endif
 ASH_EXPORT extern const char kAshEnableMirroredScreen[];
 ASH_EXPORT extern const char kAshEnablePowerButtonQuickLock[];
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index 827de483027723..84f4c3da89be31 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -6292,6 +6292,12 @@ Keep your key file in a safe place. You will need it to create new versions of y
         <message name="IDS_FLAGS_ALLOW_TOUCHPAD_THREE_FINGER_CLICK_DESCRIPTION" desc="Description for the flag to enable touchpad three finger click as middle button.">
           Enables touchpad three-finger-click as middle button.
         </message>
+        <message name="IDS_FLAGS_ASH_ENABLE_UNIFIED_DESKTOP_NAME" desc="Name for the flag to enable unified desktop mode.">
+          Enable unified desktop mode.
+        </message>
+        <message name="IDS_FLAGS_ASH_ENABLE_UNIFIED_DESKTOP_DESCRIPTION" desc="Description for the flag to enable unified desktop mode.">
+          Enable unified desktop mode which allows a window to span multiple displays.
+        </message>
         <message name="IDS_FLAGS_DISABLE_BOOT_ANIMATION" desc="Name for the flag to disable wallpaper boot animation (except for OOBE).">
           Disable boot animation.
         </message>
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 7622752bf6c2c9..5d0fe27d9213cc 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -961,6 +961,13 @@ const Experiment kExperiments[] = {
     kOsCrOS,
     SINGLE_VALUE_TYPE(chromeos::switches::kEnableTouchpadThreeFingerClick)
   },
+  {
+    "ash-enable-unified-desktop",
+    IDS_FLAGS_ASH_ENABLE_UNIFIED_DESKTOP_NAME,
+    IDS_FLAGS_ASH_ENABLE_UNIFIED_DESKTOP_DESCRIPTION,
+    kOsCrOS,
+    SINGLE_VALUE_TYPE(ash::switches::kAshEnableUnifiedDesktop)
+  },
   {
     "disable-easy-unlock",
     IDS_FLAGS_DISABLE_EASY_UNLOCK_NAME,
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 6d4aa1d39387c3..4231fa473e7b14 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -55460,6 +55460,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="-86788587" label="allow-autofill-sync-credential"/>
   <int value="-80353187" label="disable-display-color-calibration"/>
   <int value="-76631048" label="disable-offline-auto-reload-visible-only"/>
+  <int value="-70595606" label="ash-enable-unified-desktop"/>
   <int value="-68225452" label="enable-translate-new-ux"/>
   <int value="-58242474" label="ash-disable-swipe-to-close-in-overview-mode"/>
   <int value="-55944747" label="disable-child-account-detection"/>