Correct behaviour of touch wrt mouse capture.

base/win/win_util.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 "base/win/win_util.h"
 
 #include <aclapi.h>
 #include <shobjidl.h>  // Must be before propkey.
 #include <initguid.h>
 #include <propkey.h>
 #include <propvarutil.h>
 #include <sddl.h>
 #include <shlobj.h>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/win/registry.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/win/scoped_handle.h"
 #include "base/win/windows_version.h"
 
 namespace {
 
+// From MSDN.
+#define MOUSEEVENTF_FROMTOUCH 0xFF515700
+
 // TODO(gab): These definitions are temporary and should be removed once the
 // win8 SDK defines them.
 DEFINE_PROPERTYKEY(PKEY_AppUserModel_DualMode, 0x9F4C2855, 0x9F79,
                    0x4B39, 0xA8, 0xD0, 0xE1, 0xD4, 0x2D, 0xE1, 0xD5, 0xF3, 11);
 DEFINE_PROPERTYKEY(PKEY_AppUserModel_DualMode_UK, 0x9F4C2855, 0x9F79,
                    0x4B39, 0xA8, 0xD0, 0xE1, 0xD4, 0x2D, 0xE1, 0xD5, 0xF3, 18);
 
 // Sets the value of |property_key| to |property_value| in |property_store|.
 // Clears the PropVariant contained in |property_value|.
 bool SetPropVariantValueForPropertyStore(
@@ skipping 67 matching lines @@
 }
 
 bool IsCtrlPressed() {
   return (::GetKeyState(VK_CONTROL) & 0x8000) == 0x8000;
 }
 
 bool IsAltPressed() {
   return (::GetKeyState(VK_MENU) & 0x8000) == 0x8000;
 }
 
+// Windows emulates mouse messages for touch events.
+bool IsMouseEventFromTouch(UINT message) {
+  return (message == WM_MOUSEMOVE ||
+      message == WM_LBUTTONDOWN || message == WM_LBUTTONUP ||
+      message == WM_RBUTTONDOWN || message == WM_RBUTTONUP) &&
+      (GetMessageExtraInfo() & MOUSEEVENTF_FROMTOUCH) ==
+      MOUSEEVENTF_FROMTOUCH;
+}
+
 bool UserAccountControlIsEnabled() {
   // This can be slow if Windows ends up going to disk.  Should watch this key
   // for changes and only read it once, preferably on the file thread.
   //   http://code.google.com/p/chromium/issues/detail?id=61644
   base::ThreadRestrictions::ScopedAllowIO allow_io;
 
   base::win::RegKey key(HKEY_LOCAL_MACHINE,
       L"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System",
       KEY_READ);
   DWORD uac_enabled;
@@ skipping 108 matching lines @@
 
 #ifndef COPY_FILE_COPY_SYMLINK
 #error You must install the Windows 2008 or Vista Software Development Kit and \
 set it as your default include path to build this library. You can grab it by \
 searching for "download windows sdk 2008" in your favorite web search engine.  \
 Also make sure you register the SDK with Visual Studio, by selecting \
 "Integrate Windows SDK with Visual Studio 2005" from the Windows SDK \
 menu (see Start - All Programs - Microsoft Windows SDK - \
 Visual Studio Registration).
 #endif