Inline ImeTracing#onShellCommand()

This is a preparation to add new command:

  adb shell cmd ime tracing save-for-bugreport

which is to be an important piece of functionality to get rid of an
unintentional behavior change (Bug 177462676).

Anyway this CL itself is still a mechanical refactoring hence there
should be no observable behavior change.

Bug: 177462676
Test: "adb shell cmd input_method tracing start" works.
Test: "adb shell cmd input_method tracing stop" works.
Test: "adb shell ime tracing start" still works.
Test: "adb shell ime tracing stop" still works.
Test: "adb shell ime list" still works.
Change-Id: I972f287bddda962dd42d4dd5226cb8b42e759121

core/java/android/util/imetracing/ImeTracing.java

@@ -23,7 +23,6 @@ import android.inputmethodservice.AbstractInputMethodService;
 import android.os.RemoteException;
 import android.os.ServiceManager;
 import android.os.ServiceManager.ServiceNotFoundException;
-import android.os.ShellCommand;
 import android.util.Log;
 import android.util.proto.ProtoOutputStream;
 import android.view.inputmethod.InputMethodManager;
@@ -103,12 +102,6 @@ public abstract class ImeTracing {
      */
     public abstract void addToBuffer(ProtoOutputStream proto, int source);
 
-    /**
-     * @param shell The shell command to process
-     * @return {@code 0} if the command was successfully processed, {@code -1} otherwise
-     */
-    public abstract int onShellCommand(ShellCommand shell);
-
     /**
      * Starts a proto dump of the client side information.
      *

core/java/android/util/imetracing/ImeTracingClientImpl.java

@@ -20,7 +20,6 @@ import android.annotation.NonNull;
 import android.inputmethodservice.AbstractInputMethodService;
 import android.os.RemoteException;
 import android.os.ServiceManager.ServiceNotFoundException;
-import android.os.ShellCommand;
 import android.util.Log;
 import android.util.proto.ProtoOutputStream;
 import android.view.inputmethod.InputMethodManager;
@@ -44,11 +43,6 @@ class ImeTracingClientImpl extends ImeTracing {
     public void addToBuffer(ProtoOutputStream proto, int source) {
     }
 
-    @Override
-    public int onShellCommand(ShellCommand shell) {
-        return -1;
-    }
-
     @Override
     public void triggerClientDump(String where, @NonNull InputMethodManager immInstance,
             ProtoOutputStream icProto) {

core/java/android/util/imetracing/ImeTracingServerImpl.java

@@ -22,7 +22,6 @@ import android.annotation.Nullable;
 import android.inputmethodservice.AbstractInputMethodService;
 import android.os.RemoteException;
 import android.os.ServiceManager.ServiceNotFoundException;
-import android.os.ShellCommand;
 import android.util.Log;
 import android.util.proto.ProtoOutputStream;
 import android.view.inputmethod.InputMethodEditorTraceProto.InputMethodClientsTraceFileProto;
@@ -106,32 +105,6 @@ class ImeTracingServerImpl extends ImeTracing {
         }
     }
 
-    /**
-     * Responds to a shell command of the format "adb shell cmd input_method ime tracing <command>"
-     *
-     * @param shell The shell command to process
-     * @return {@code 0} if the command was valid and successfully processed, {@code -1} otherwise
-     */
-    @Override
-    public int onShellCommand(ShellCommand shell) {
-        PrintWriter pw = shell.getOutPrintWriter();
-        String cmd = shell.getNextArgRequired();
-        switch (cmd) {
-            case "start":
-                startTrace(pw);
-                return 0;
-            case "stop":
-                stopTrace(pw);
-                return 0;
-            default:
-                pw.println("Unknown command: " + cmd);
-                pw.println("Input method trace options:");
-                pw.println("  start: Start tracing");
-                pw.println("  stop: Stop tracing");
-                return -1;
-        }
-    }
-
     @Override
     public void triggerClientDump(String where, InputMethodManager immInstance,
             ProtoOutputStream icProto) {

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

@@ -5838,7 +5838,22 @@ public class InputMethodManagerService extends IInputMethodManager.Stub
     @BinderThread
     @ShellCommandResult
     private int handleShellCommandTraceInputMethod(@NonNull ShellCommand shellCommand) {
-        int result = ImeTracing.getInstance().onShellCommand(shellCommand);
+        final String cmd = shellCommand.getNextArgRequired();
+        final PrintWriter pw = shellCommand.getOutPrintWriter();
+        switch (cmd) {
+            case "start":
+                ImeTracing.getInstance().getInstance().startTrace(pw);
+                break;
+            case "stop":
+                ImeTracing.getInstance().stopTrace(pw);
+                break;
+            default:
+                pw.println("Unknown command: " + cmd);
+                pw.println("Input method trace options:");
+                pw.println("  start: Start tracing");
+                pw.println("  stop: Stop tracing");
+                return ShellCommandResult.FAILURE;
+        }
         boolean isImeTraceEnabled = ImeTracing.getInstance().isEnabled();
         ArrayMap<IBinder, ClientState> clients;
         synchronized (mMethodMap) {
@@ -5854,7 +5869,7 @@ public class InputMethodManagerService extends IInputMethodManager.Stub
                 }
             }
         }
-        return result;
+        return ShellCommandResult.SUCCESS;
     }
 
     /**