Introduce ViewRoot forwarding input/view events to native

ui/android/view_root.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/android/view_root.h"
+
+#include <jni.h>
+#include <string>
+#include <vector>
+
+#include "base/android/jni_weak_ref.h"
+#include "base/android/scoped_java_ref.h"
+#include "base/macros.h"
+#include "base/observer_list.h"
+#include "base/time/time.h"
+#include "jni/ViewRoot_jni.h"
+#include "ui/android/ui_android_export.h"
+#include "ui/android/view_android.h"
+#include "ui/gfx/geometry/vector2d_f.h"
+
+namespace ui {
+
+using base::android::JavaParamRef;
+using base::android::JavaRef;
+using base::android::ScopedJavaLocalRef;
+
+ViewRoot::ViewRoot() {}
+
+ViewRoot::ViewRoot(JNIEnv* env,
+                   const base::android::JavaParamRef<jobject>& obj,
+                   jlong jwindow_android) :
+    java_obj_(env, obj) {
+  WindowAndroid* window_android =
+          reinterpret_cast<WindowAndroid*>(jwindow_android);
+  DCHECK(window_android);
+  window_ = window_android;
+}
+
+ViewRoot::~ViewRoot() {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  const ScopedJavaLocalRef<jobject> view_root = java_obj_.get(env);
+  if (!view_root.is_null())
+    Java_ViewRoot_onDestroyNativeView(env, view_root);
+}
+
+ViewAndroid* ViewRoot::GetViewRoot() {
+  return this;
+}
+
+WindowAndroid* ViewRoot::GetWindowAndroid() const {
+  return window_;
+}
+
+void ViewRoot::SetWindowAndroid(WindowAndroid* window) {
+  window_ = window;
+}
+
+// static
+void ViewRoot::OnPhysicalBackingSizeChanged(JNIEnv* env,
+                                            const JavaParamRef<jobject>& jobj,
+                                            int width,
+                                            int height) {
+  OnPhysicalBackingSizeChangedInternal(width, height);
+}
+
+// static
+ViewRoot* ViewRoot::FromJavaObject(JNIEnv* env,
+                                   const JavaParamRef<jobject>& obj) {
+  if (obj.is_null())
+    return nullptr;
+  return reinterpret_cast<ViewRoot*>(Java_ViewRoot_getNativePtr(env, obj));
+}
+
+// static
+jlong Init(JNIEnv* env,
+           const JavaParamRef<jobject>& obj,
+           jlong window_android) {
+  return reinterpret_cast<intptr_t>(new ViewRoot(env, obj, window_android));
+}
+
+bool RegisterViewRoot(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+}  // namespace ui