Revert "Deduplicate plugin registration logic and make error logs visible (#25297)"

This reverts commit 443e6275.

shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java

@@ -20,7 +20,6 @@ import io.flutter.embedding.engine.plugins.activity.ActivityControlSurface;
 import io.flutter.embedding.engine.plugins.broadcastreceiver.BroadcastReceiverControlSurface;
 import io.flutter.embedding.engine.plugins.contentprovider.ContentProviderControlSurface;
 import io.flutter.embedding.engine.plugins.service.ServiceControlSurface;
-import io.flutter.embedding.engine.plugins.util.GeneratedPluginRegister;
 import io.flutter.embedding.engine.renderer.FlutterRenderer;
 import io.flutter.embedding.engine.renderer.RenderSurface;
 import io.flutter.embedding.engine.systemchannels.AccessibilityChannel;
@@ -37,6 +36,7 @@ import io.flutter.embedding.engine.systemchannels.SystemChannel;
 import io.flutter.embedding.engine.systemchannels.TextInputChannel;
 import io.flutter.plugin.localization.LocalizationPlugin;
 import io.flutter.plugin.platform.PlatformViewsController;
+import java.lang.reflect.Method;
 import java.util.HashSet;
 import java.util.Set;
 
@@ -342,7 +342,7 @@ public class FlutterEngine {
     // Only automatically register plugins if both constructor parameter and
     // loaded AndroidManifest config turn this feature on.
     if (automaticallyRegisterPlugins && flutterLoader.automaticallyRegisterPlugins()) {
-      GeneratedPluginRegister.registerGeneratedPlugins(this);
+      registerPlugins();
     }
   }
 
@@ -391,6 +391,36 @@ public class FlutterEngine {
         newFlutterJNI); // FlutterJNI.
   }
 
+  /**
+   * Registers all plugins that an app lists in its pubspec.yaml.
+   *
+   * <p>The Flutter tool generates a class called GeneratedPluginRegistrant, which includes the code
+   * necessary to register every plugin in the pubspec.yaml with a given {@code FlutterEngine}. The
+   * GeneratedPluginRegistrant must be generated per app, because each app uses different sets of
+   * plugins. Therefore, the Android embedding cannot place a compile-time dependency on this
+   * generated class. This method uses reflection to attempt to locate the generated file and then
+   * use it at runtime.
+   *
+   * <p>This method fizzles if the GeneratedPluginRegistrant cannot be found or invoked. This
+   * situation should never occur, but if any eventuality comes up that prevents an app from using
+   * this behavior, that app can still write code that explicitly registers plugins.
+   */
+  private void registerPlugins() {
+    try {
+      Class<?> generatedPluginRegistrant =
+          Class.forName("io.flutter.plugins.GeneratedPluginRegistrant");
+      Method registrationMethod =
+          generatedPluginRegistrant.getDeclaredMethod("registerWith", FlutterEngine.class);
+      registrationMethod.invoke(null, this);
+    } catch (Exception e) {
+      Log.w(
+          TAG,
+          "Tried to automatically register plugins with FlutterEngine ("
+              + this
+              + ") but could not find and invoke the GeneratedPluginRegistrant.");
+    }
+  }
+
   /**
    * Cleans up all components within this {@code FlutterEngine} and destroys the associated Dart
    * Isolate. All state held by the Dart Isolate, such as the Flutter Elements tree, is lost.

shell/platform/android/io/flutter/embedding/engine/plugins/util/GeneratedPluginRegister.java

@@ -33,15 +33,11 @@ public class GeneratedPluginRegister {
           generatedPluginRegistrant.getDeclaredMethod("registerWith", FlutterEngine.class);
       registrationMethod.invoke(null, flutterEngine);
     } catch (Exception e) {
-      Log.e(
+      Log.w(
           TAG,
           "Tried to automatically register plugins with FlutterEngine ("
               + flutterEngine
               + ") but could not find and invoke the GeneratedPluginRegistrant.");
-      Log.e(
-          TAG,
-          // getCause here because the first layer of the exception would be from reflect.
-          "Received exception while registering: " + e.getCause());
     }
   }
 }

shell/platform/android/test/io/flutter/embedding/engine/FlutterEngineTest.java

@@ -35,7 +35,6 @@ import org.mockito.stubbing.Answer;
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.RuntimeEnvironment;
 import org.robolectric.annotation.Config;
-import org.robolectric.shadows.ShadowLog;
 
 @Config(manifest = Config.NONE)
 @RunWith(RobolectricTestRunner.class)
@@ -64,9 +63,6 @@ public class FlutterEngineTest {
   @After
   public void tearDown() {
     GeneratedPluginRegistrant.clearRegisteredEngines();
-    // Make sure to not forget to remove the mock exception in the generated plugin registration
-    // mock, or everything subsequent will break.
-    GeneratedPluginRegistrant.pluginRegistrationException = null;
   }
 
   @Test
@@ -82,38 +78,6 @@ public class FlutterEngineTest {
     assertEquals(flutterEngine, registeredEngines.get(0));
   }
 
-  // Helps show the root cause of MissingPluginException type errors like
-  // https://github.com/flutter/flutter/issues/78625.
-  @Test
-  public void itCatchesAndDisplaysRegistrationExceptions() {
-    assertTrue(GeneratedPluginRegistrant.getRegisteredEngines().isEmpty());
-    GeneratedPluginRegistrant.pluginRegistrationException =
-        new RuntimeException("I'm a bug in the plugin");
-    FlutterLoader mockFlutterLoader = mock(FlutterLoader.class);
-    when(mockFlutterLoader.automaticallyRegisterPlugins()).thenReturn(true);
-    FlutterEngine flutterEngine =
-        new FlutterEngine(RuntimeEnvironment.application, mockFlutterLoader, flutterJNI);
-
-    List<FlutterEngine> registeredEngines = GeneratedPluginRegistrant.getRegisteredEngines();
-    // When it crashes, it doesn't end up registering anything.
-    assertEquals(0, registeredEngines.size());
-
-    // Check the logs actually says registration failed, so a subsequent MissingPluginException
-    // isn't mysterious.
-    assertTrue(
-        ShadowLog.getLogsForTag("GeneratedPluginsRegister")
-            .get(0)
-            .msg
-            .contains("Tried to automatically register plugins"));
-    assertTrue(
-        ShadowLog.getLogsForTag("GeneratedPluginsRegister")
-            .get(1)
-            .msg
-            .contains("I'm a bug in the plugin"));
-
-    GeneratedPluginRegistrant.pluginRegistrationException = null;
-  }
-
   @Test
   public void itDoesNotAutomaticallyRegistersPluginsWhenFlutterLoaderDisablesIt() {
     assertTrue(GeneratedPluginRegistrant.getRegisteredEngines().isEmpty());
@@ -141,6 +105,18 @@ public class FlutterEngineTest {
     assertTrue(registeredEngines.isEmpty());
   }
 
+  @Test
+  public void itCanBeConfiguredToNotAutomaticallyRegisterPlugins() {
+    new FlutterEngine(
+        RuntimeEnvironment.application,
+        mock(FlutterLoader.class),
+        flutterJNI,
+        /*dartVmArgs=*/ new String[] {},
+        /*automaticallyRegisterPlugins=*/ false);
+
+    assertTrue(GeneratedPluginRegistrant.getRegisteredEngines().isEmpty());
+  }
+
   @Test
   public void itNotifiesPlatformViewsControllerWhenDevHotRestart() {
     // Setup test.

shell/platform/android/test/io/flutter/plugins/GeneratedPluginRegistrant.java

@@ -13,7 +13,6 @@ import java.util.List;
 @VisibleForTesting
 public class GeneratedPluginRegistrant {
   private static final List<FlutterEngine> registeredEngines = new ArrayList<>();
-  public static RuntimeException pluginRegistrationException;
 
   /**
    * The one and only method currently generated by the tool.
@@ -22,9 +21,6 @@ public class GeneratedPluginRegistrant {
    * all registered engines instead.
    */
   public static void registerWith(FlutterEngine engine) {
-    if (pluginRegistrationException != null) {
-      throw pluginRegistrationException;
-    }
     registeredEngines.add(engine);
   }