[Remoting Android] Refactor CursorShapeStubProxy from JniDisplayHandler

remoting/client/jni/jni_display_handler.cc

Index: remoting/client/jni/jni_display_handler.cc
diff --git a/remoting/client/jni/jni_display_handler.cc b/remoting/client/jni/jni_display_handler.cc
index e139e7bc3ab7578af1345d9402a27e9e3a595c42..bf26e28225a0465dfb1518f77fd19a26414ee0e0 100644
--- a/remoting/client/jni/jni_display_handler.cc
+++ b/remoting/client/jni/jni_display_handler.cc
@@ -10,6 +10,7 @@
 #include "base/memory/ptr_util.h"
 #include "base/stl_util.h"
 #include "jni/Display_jni.h"
+#include "remoting/client/callback_cursor_shape_stub.h"
 #include "remoting/client/jni/chromoting_jni_runtime.h"
 #include "remoting/client/jni/jni_client.h"
 #include "remoting/client/jni/jni_video_renderer.h"
@@ -24,33 +25,6 @@ const int kBytesPerPixel = 4;
 
 namespace remoting {
 
-// CursorShapeStub with a lifetime separated from JniDisplayHandler.
-class DisplayCursorShapeStub : public protocol::CursorShapeStub {
- public:
-  DisplayCursorShapeStub(
-      base::WeakPtr<JniDisplayHandler> display,
-      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
-  void SetCursorShape(const protocol::CursorShapeInfo& cursor_shape) override;
- private:
-  base::WeakPtr<JniDisplayHandler> display_handler_;
-  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
-};
-
-DisplayCursorShapeStub::DisplayCursorShapeStub(
-    base::WeakPtr<JniDisplayHandler> display,
-    scoped_refptr<base::SingleThreadTaskRunner> task_runner) :
-        display_handler_(display),
-        task_runner_(task_runner) {
-}
-
-void DisplayCursorShapeStub::SetCursorShape(
-    const protocol::CursorShapeInfo& cursor_shape) {
-  task_runner_->PostTask(FROM_HERE,
-                         base::Bind(&JniDisplayHandler::UpdateCursorShape,
-                                    display_handler_,
-                                    cursor_shape));
-}
-
 // JniDisplayHandler definitions.
 JniDisplayHandler::JniDisplayHandler(ChromotingJniRuntime* runtime)
     : runtime_(runtime),
@@ -95,8 +69,9 @@ void JniDisplayHandler::UpdateCursorShape(
 
 std::unique_ptr<protocol::CursorShapeStub>
 JniDisplayHandler::CreateCursorShapeStub() {
-  return base::WrapUnique(
-      new DisplayCursorShapeStub(weak_ptr_, runtime_->display_task_runner()));
+  return base::WrapUnique(new CallbackCursorShapeStub(
+      base::Bind(&JniDisplayHandler::UpdateCursorShape, weak_ptr_),
+      runtime_->display_task_runner()));
 }
 
 std::unique_ptr<protocol::VideoRenderer>