Use Event to render feedback animations.

remoting/android/java/src/org/chromium/chromoting/EventParameters.java

+// 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.
+
+package org.chromium.chromoting;
+
+import android.graphics.Canvas;
+import android.graphics.Point;
+
+/** A class for all {@link Event} parameters. */
+public final class EventParameters {

[Lambros, 2016/06/01 23:51:36]

These various EventParameters.* classes will not be
related to each other, so they should be in separate
files.

Perhaps use a Java package, or a common name
prefix such as
EventParametersFoo, EventParametersBar.
Or have EventParametersFoo be an inner class of
Foo.

[Hzj_jie, 2016/06/02 02:21:37]

During prototyping before, I found lots of events can share same or similar
event parameters, so a parameter is not directly binding to its consumers. But
using a new namespace in java is not so friendly, it does not provide 'searching
from current namespace' function. So I am OK to move them into individual files.

+    /** The parameter for an OnPaint event. */
+    public static final class Paint {
+        public final Point cursorPosition;
+        public final Canvas canvas;
+        public final float scale;
+
+        public Paint(Point cursorPosition, Canvas canvas, float scale) {

[Lambros, 2016/06/01 23:51:36]

PaintAnimation?

[Hzj_jie, 2016/06/02 02:21:37]

Same reason as mOnPaint field and onPaint() function in DesktopView.

+            this.cursorPosition = cursorPosition;
+            this.canvas = canvas;
+            this.scale = scale;
+        }
+    }
+}