Extract part of the client switch logic

Bug: 205676419
Test: make
Change-Id: If387b0f0d007ca468f3a038693ca2014d8e671d6

services/core/java/com/android/server/inputmethod/InputMethodManagerService.java

@@ -2447,14 +2447,7 @@ public class InputMethodManagerService extends IInputMethodManager.Stub
         mImeHiddenByDisplayPolicy = false;
 
         if (mCurClient != cs) {
-            // If the client is changing, we need to switch over to the new
-            // one.
-            unbindCurrentClientLocked(UnbindReason.SWITCH_CLIENT);
-            // If the screen is on, inform the new client it is active
-            if (mIsInteractive) {
-                scheduleSetActiveToClient(cs, true /* active */, false /* fullscreen */,
-                        false /* reportToImeController */);
-            }
+            prepareClientSwitchLocked(cs);
         }
 
         // Bump up the sequence for this client and attach it.
@@ -2523,6 +2516,18 @@ public class InputMethodManagerService extends IInputMethodManager.Stub
         return InputBindResult.IME_NOT_CONNECTED;
     }
 
+    @GuardedBy("mMethodMap")
+    private void prepareClientSwitchLocked(ClientState cs) {
+        // If the client is changing, we need to switch over to the new
+        // one.
+        unbindCurrentClientLocked(UnbindReason.SWITCH_CLIENT);
+        // If the screen is on, inform the new client it is active
+        if (mIsInteractive) {
+            scheduleSetActiveToClient(cs, true /* active */, false /* fullscreen */,
+                    false /* reportToImeController */);
+        }
+    }
+
     @NonNull
     private Intent createImeBindingIntent(ComponentName component) {
         Intent intent = new Intent(InputMethod.SERVICE_INTERFACE);