Improve scroll performance on Windows 10 with high precision touchpads.

ui/views/win/hwnd_message_handler.cc

 // 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.
 
 #include "ui/views/win/hwnd_message_handler.h"
 
 #include <dwmapi.h>
 #include <oleacc.h>
 #include <shellapi.h>
 
@@ skipping 354 matching lines @@
     if (!(current_style & WS_POPUP)) {
       AddScrollStylesToWindow(hwnd());
       needs_scroll_styles_ = true;
     }
   }
 #endif
 
   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) {
   if (modal_type == ui::MODAL_TYPE_NONE)
     return;
   // We implement modality by crawling up the hierarchy of windows starting
   // at the owner, disabling all of them so that they don't receive input
   // messages.
   HWND start = ::GetWindow(hwnd(), GW_OWNER);
   while (start) {
@@ skipping 121 matching lines @@
                bounds_in_pixels.width(), bounds_in_pixels.height(),
                SWP_NOACTIVATE | SWP_NOZORDER);
 
   // If HWND size is not changed, we will not receive standard size change
   // notifications. If |force_size_changed| is |true|, we should pretend size is
   // changed.
   if (old_size == bounds_in_pixels.size() && force_size_changed) {
     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) {
   SetWindowPos(hwnd(), NULL, 0, 0, size.width(), size.height(),
                SWP_NOACTIVATE | SWP_NOZORDER | SWP_NOMOVE);
 }
 
 void HWNDMessageHandler::CenterWindow(const gfx::Size& size) {
   HWND parent = GetParent(hwnd());
   if (!IsWindow(hwnd()))
@@ skipping 21 matching lines @@
 
 void HWNDMessageHandler::Show() {
   if (IsWindow(hwnd())) {
     if (!(GetWindowLong(hwnd(), GWL_EXSTYLE) & WS_EX_TRANSPARENT) &&
         !(GetWindowLong(hwnd(), GWL_EXSTYLE) & WS_EX_NOACTIVATE)) {
       ShowWindowWithState(ui::SHOW_STATE_NORMAL);
     } else {
       ShowWindowWithState(ui::SHOW_STATE_INACTIVE);
     }
   }
+  if (direct_manipulation_helper_)
+    direct_manipulation_helper_->Activate(hwnd());
 }
 
 void HWNDMessageHandler::ShowWindowWithState(ui::WindowShowState show_state) {
   TRACE_EVENT0("views", "HWNDMessageHandler::ShowWindowWithState");
   DWORD native_show_state;
   switch (show_state) {
     case ui::SHOW_STATE_INACTIVE:
       native_show_state = SW_SHOWNOACTIVATE;
       break;
     case ui::SHOW_STATE_MAXIMIZED:
@@ skipping 2097 matching lines @@
   base::WeakPtr<HWNDMessageHandler> ref(weak_factory_.GetWeakPtr());
   bool handled = delegate_->HandleMouseEvent(event);
 
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed.
   tracked_objects::ScopedTracker tracking_profile8(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "440919 HWNDMessageHandler::HandleMouseEventInternal8"));
 
   if (!ref.get())
     return 0;
+
+  if (direct_manipulation_helper_ &&
+      (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.
     tracked_objects::ScopedTracker tracking_profile9(
         FROM_HERE_WITH_EXPLICIT_FUNCTION(
             "440919 HWNDMessageHandler::HandleMouseEventInternal9"));
 
     // TODO(msw): Eliminate undesired painting, or re-evaluate this workaround.
     // DefWindowProc for WM_NCLBUTTONDOWN does weird non-client painting, so we
     // need to call it inside a ScopedRedrawLock. This may cause other negative
@@ skipping 56 matching lines @@
     SetWindowPos(hwnd(), NULL, 0, 0, 0, 0, flags | SWP_HIDEWINDOW);
     SetWindowPos(hwnd(), NULL, 0, 0, 0, 0, flags | SWP_SHOWWINDOW);
   }
   // WM_DWMCOMPOSITIONCHANGED is only sent to top level windows, however we want
   // to notify our children too, since we can have MDI child windows who need to
   // update their appearance.
   EnumChildWindows(hwnd(), &SendDwmCompositionChanged, NULL);
 }
 
 }  // namespace views