Port touch-demo.sky to Dart and make it work in SkyShell

sky/shell/platform_view.cc

 // Copyright 2015 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 "sky/shell/platform_view.h"
 
 #include <android/input.h>
 #include <android/native_window_jni.h>
 
 #include "base/android/jni_android.h"
 #include "base/bind.h"
 #include "base/location.h"
 #include "jni/PlatformView_jni.h"
 #include "sky/shell/shell.h"
 
 namespace sky {
 namespace shell {
 
-static jlong Attach(JNIEnv* env, jclass clazz) {
-  return reinterpret_cast<jlong>(Shell::Shared().view());
+static jlong Attach(JNIEnv* env, jclass clazz, jint viewportObserverHandle) {
+  PlatformView* view = Shell::Shared().view();
+  view->ConnectToViewportObserver(
+      mojo::MakeRequest<ViewportObserver>(mojo::ScopedMessagePipeHandle(
+          mojo::MessagePipeHandle(viewportObserverHandle))));
+  return reinterpret_cast<jlong>(view);
 }
 
 // static
 bool PlatformView::Register(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 PlatformView::PlatformView(const Config& config)
     : config_(config), window_(nullptr) {
 }
 
 PlatformView::~PlatformView() {
   if (window_)
     ReleaseWindow();
 }
 
+void PlatformView::ConnectToViewportObserver(
+    mojo::InterfaceRequest<ViewportObserver> request) {
+  config_.ui_task_runner->PostTask(
+      FROM_HERE,
+      base::Bind(&UIDelegate::ConnectToViewportObserver, config_.ui_delegate,
+                 base::Passed(&request)));
+}
+
 void PlatformView::Detach(JNIEnv* env, jobject obj) {
   DCHECK(!window_);
 }
 
 void PlatformView::SurfaceCreated(JNIEnv* env, jobject obj, jobject jsurface) {
   base::android::ScopedJavaLocalRef<jobject> protector(env, jsurface);
   // Note: This ensures that any local references used by
   // ANativeWindow_fromSurface are released immediately. This is needed as a
   // workaround for https://code.google.com/p/android/issues/detail?id=68174
   {
     base::android::ScopedJavaLocalFrame scoped_local_reference_frame(env);
     window_ = ANativeWindow_fromSurface(env, jsurface);
   }
   config_.gpu_task_runner->PostTask(
       FROM_HERE, base::Bind(&GPUDelegate::OnAcceleratedWidgetAvailable,
                             config_.gpu_delegate, window_));
 }
 
 void PlatformView::SurfaceDestroyed(JNIEnv* env, jobject obj) {
   DCHECK(window_);
   config_.gpu_task_runner->PostTask(
       FROM_HERE,
       base::Bind(&GPUDelegate::OnOutputSurfaceDestroyed, config_.gpu_delegate));
   ReleaseWindow();
 }
 
-void PlatformView::SurfaceSetSize(JNIEnv* env,
-                                  jobject obj,
-                                  jint width,
-                                  jint height,
-                                  jfloat density) {
-  config_.ui_task_runner->PostTask(
-      FROM_HERE,
-      base::Bind(&UIDelegate::OnViewportMetricsChanged, config_.ui_delegate,
-                 gfx::Size(width, height), density));
-}
-
 void PlatformView::ReleaseWindow() {
   ANativeWindow_release(window_);
   window_ = nullptr;
 }
 
 }  // namespace shell
 }  // namespace sky