Improve scroll performance on Windows 10 with high precision touchpads.

ui/views/win/hwnd_message_handler.cc

Index: ui/views/win/hwnd_message_handler.cc
diff --git a/ui/views/win/hwnd_message_handler.cc b/ui/views/win/hwnd_message_handler.cc
index 5cadce12e659ca63c5f77da150f69f00405552f3..821a935043ac638b4b4f68e403e7ebde4f90e94c 100644
--- a/ui/views/win/hwnd_message_handler.cc
+++ b/ui/views/win/hwnd_message_handler.cc
@@ -372,6 +372,13 @@ void HWNDMessageHandler::Init(HWND parent, const gfx::Rect& bounds) {
   prop_window_target_.reset(new ui::ViewProp(hwnd(),
                             ui::WindowEventTarget::kWin32InputEventTarget,
                             static_cast<ui::WindowEventTarget*>(this)));
+
+  // Direct Manipulation is enabled on Windows 10+. The CreateInstance function
+  // returns NULL if Direct Manipulation is not available.
+  direct_manipulation_helper_.reset(
+      gfx::win::DirectManipulationHelper::CreateInstance());
+  if (direct_manipulation_helper_)
+    direct_manipulation_helper_->Initialize(hwnd());
 }
 
 void HWNDMessageHandler::InitModalType(ui::ModalType modal_type) {
@@ -513,6 +520,9 @@ void HWNDMessageHandler::SetBounds(const gfx::Rect& bounds_in_pixels,
     delegate_->HandleClientSizeChanged(GetClientAreaBounds().size());
     ResetWindowRegion(false, true);
   }
+
+  if (direct_manipulation_helper_)
+    direct_manipulation_helper_->SetBounds(bounds_in_pixels);
 }
 
 void HWNDMessageHandler::SetSize(const gfx::Size& size) {
@@ -554,6 +564,8 @@ void HWNDMessageHandler::Show() {
       ShowWindowWithState(ui::SHOW_STATE_INACTIVE);
     }
   }
+  if (direct_manipulation_helper_)
+    direct_manipulation_helper_->Activate(hwnd());
 }
 
 void HWNDMessageHandler::ShowWindowWithState(ui::WindowShowState show_state) {
@@ -2671,6 +2683,13 @@ LRESULT HWNDMessageHandler::HandleMouseEventInternal(UINT message,
 
   if (!ref.get())
     return 0;
+
+  if (direct_manipulation_helper_ && track_mouse &&
+      (message == WM_MOUSEWHEEL || message == WM_MOUSEHWHEEL)) {
+    direct_manipulation_helper_->HandleMouseWheel(hwnd(), message, w_param,
+        l_param);
+  }
+
   if (!handled && message == WM_NCLBUTTONDOWN && w_param != HTSYSMENU &&
       delegate_->IsUsingCustomFrame()) {
     // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed.