Integrate AndroidSwitch into Fabric on Android

Summary:
In this diff we integrate the Switch component on Android in Fabric. Since the component has a custom measure function, we need to write some C++ to call the measure method in Java.

The component isn't fully functional yet (setNativeProps isn't supported in Fabric) and has some problems with measuring itself. I will fix the component in the next diffs in this stack.

Reviewed By: JoshuaGross

Differential Revision: D17571258

fbshipit-source-id: be4e201495b9b197ddec44ee3484357bfb6225a8

ReactCommon/fabric/components/switch/androidswitch/AndroidSwitchShadowNode.cpp

@@ -0,0 +1,30 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include "AndroidSwitchShadowNode.h"
+
+namespace facebook {
+namespace react {
+
+extern const char AndroidSwitchComponentName[] = "AndroidSwitch";
+
+void AndroidSwitchShadowNode::setAndroidSwitchMeasurementsManager(
+    const std::shared_ptr<AndroidSwitchMeasurementsManager>
+        &measurementsManager) {
+  ensureUnsealed();
+  measurementsManager_ = measurementsManager;
+}
+
+#pragma mark - LayoutableShadowNode
+
+Size AndroidSwitchShadowNode::measure(
+    LayoutConstraints layoutConstraints) const {
+  return measurementsManager_->measure(layoutConstraints);
+}
+
+} // namespace react
+} // namespace facebook