Revert of Remove supports_touch_events flag from BasicDesktopEnvironment

remoting/host/basic_desktop_environment.h

Index: remoting/host/basic_desktop_environment.h
diff --git a/remoting/host/basic_desktop_environment.h b/remoting/host/basic_desktop_environment.h
index 222c1768e76bdd7676b21cda8fcb1b52bc6d0ae9..5bf983aec4b24b1c07ef120fe6ae9c6c236fddf5 100644
--- a/remoting/host/basic_desktop_environment.h
+++ b/remoting/host/basic_desktop_environment.h
@@ -46,7 +46,8 @@
       scoped_refptr<base::SingleThreadTaskRunner> caller_task_runner,
       scoped_refptr<base::SingleThreadTaskRunner> video_capture_task_runner,
       scoped_refptr<base::SingleThreadTaskRunner> input_task_runner,
-      scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner);
+      scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner,
+      bool supports_touch_events);
 
   scoped_refptr<base::SingleThreadTaskRunner> caller_task_runner() const {
     return caller_task_runner_;
@@ -90,6 +91,9 @@
   // find build errors.
   std::unique_ptr<webrtc::DesktopCaptureOptions> desktop_capture_options_;
 
+  // True if the touch events capability should be offered.
+  const bool supports_touch_events_;
+
   DISALLOW_COPY_AND_ASSIGN(BasicDesktopEnvironment);
 };
 
@@ -105,6 +109,10 @@
 
   // DesktopEnvironmentFactory implementation.
   bool SupportsAudioCapture() const override;
+
+  void set_supports_touch_events(bool enable) {
+    supports_touch_events_ = enable;
+  }
 
  protected:
   scoped_refptr<base::SingleThreadTaskRunner> caller_task_runner() const {
@@ -124,6 +132,8 @@
     return ui_task_runner_;
   }
 
+  bool supports_touch_events() const { return supports_touch_events_; }
+
  private:
   // Task runner on which methods of DesktopEnvironmentFactory interface should
   // be called.
@@ -138,6 +148,10 @@
   // Used to run UI code.
   scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;
 
+  // True if the touch events capability should be offered by the
+  // DesktopEnvironment instances.
+  bool supports_touch_events_;
+
   DISALLOW_COPY_AND_ASSIGN(BasicDesktopEnvironmentFactory);
 };