Make Interaction Media Features MQ dynamic on Linux.

content/browser/renderer_host/input/input_device_change_observer.cc

Index: content/browser/renderer_host/input/input_device_change_observer.cc
diff --git a/content/browser/renderer_host/input/input_device_change_observer.cc b/content/browser/renderer_host/input/input_device_change_observer.cc
index 7ef1041c01170bb3d2f3653ec115d74932de39ea..f8481a6ef2d9adb38b68e99f9cc4533036c8000b 100644
--- a/content/browser/renderer_host/input/input_device_change_observer.cc
+++ b/content/browser/renderer_host/input/input_device_change_observer.cc
@@ -8,6 +8,8 @@
 
 #if defined(OS_WIN)
 #include "ui/events/devices/input_device_observer_win.h"
+#elif defined(OS_LINUX)
+#include "ui/events/devices/device_data_manager.h"
 #endif
 
 namespace content {
@@ -16,12 +18,16 @@ InputDeviceChangeObserver::InputDeviceChangeObserver(RenderViewHost* rvh) {
   render_view_host_ = rvh;
 #if defined(OS_WIN)
   ui::InputDeviceObserverWin::GetInstance()->AddObserver(this);
+#elif defined(OS_LINUX)
+  ui::DeviceDataManager::GetInstance()->AddObserver(this);

[sadrul, 2017/05/10 01:47:53]

I have left a comment in https://codereview.chromium.org/2690323002/#msg84

This should be:
 
#if defined(OS_WIN) || defined(OS_LINUX)
  ui::InputDeviceManager::GetInstance()->AddObserver(this);
#endif

 #endif
 }
 
 InputDeviceChangeObserver::~InputDeviceChangeObserver() {
 #if defined(OS_WIN)
   ui::InputDeviceObserverWin::GetInstance()->RemoveObserver(this);
+#elif defined(OS_LINUX)
+  ui::DeviceDataManager::GetInstance()->RemoveObserver(this);
 #endif
   render_view_host_ = nullptr;
 }