Add MouseClampingFilter and update ClientSession to use it.

remoting/host/mouse_clamping_filter.h

Index: remoting/host/mouse_clamping_filter.h
diff --git a/remoting/host/mouse_clamping_filter.h b/remoting/host/mouse_clamping_filter.h
new file mode 100644
index 0000000000000000000000000000000000000000..02ff17a214cb80255670012c92bd773fd2fe3581
--- /dev/null
+++ b/remoting/host/mouse_clamping_filter.h
@@ -0,0 +1,35 @@
+// Copyright (c) 2012 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.
+
+#ifndef REMOTING_HOST_MOUSE_CLAMPING_FILTER_H_
+#define REMOTING_HOST_MOUSE_CLAMPING_FILTER_H_
+
+#include "base/compiler_specific.h"
+#include "remoting/protocol/mouse_input_filter.h"
+
+namespace remoting {
+
+class VideoFrameCapturer;
+
+// Filtering InputStub implementation which clamps mouse each mouse event to
+// the current dimensions of a VideoFrameCapturer instance before passing
+// them on to the target |input_stub|.
+class MouseClampingFilter : public protocol::MouseInputFilter {

[simonmorris, 2012/08/20 19:47:04]

Implementation inheritance is brittle. It'd be better to delegate to a
MouseInputFilter member.

[Wez, 2012/08/20 20:26:25]

I agree in principle but this is such a trivial implementation that delegation
added more boilerplate than I felt was worth it.

I've re-expressed this as an InputFilter that accepts the MouseInputFilter to
configure as a ctor parameter, and sets it as the target InputStub.

+ public:
+  MouseClampingFilter(VideoFrameCapturer* capturer,
+                      protocol::InputStub* input_stub);
+  virtual ~MouseClampingFilter();
+
+  // InputStub overrides.
+  virtual void InjectMouseEvent(const protocol::MouseEvent& event) OVERRIDE;
+
+ private:
+  VideoFrameCapturer* capturer_;
+
+  DISALLOW_COPY_AND_ASSIGN(MouseClampingFilter);
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_MOUSE_CLAMPING_FILTER_H_