Add scroll and gesture message filters for UIPI Flash.

chrome/browser/renderer_host/render_widget_host_view_win.cc

Index: chrome/browser/renderer_host/render_widget_host_view_win.cc
===================================================================
--- chrome/browser/renderer_host/render_widget_host_view_win.cc	(revision 96873)
+++ chrome/browser/renderer_host/render_widget_host_view_win.cc	(working copy)
@@ -2,6 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// Need Win 7 headers for WM_GESTURE and ChangeWindowMessageFilterEx
+// TODO(jschuh): See crbug.com/92941 for longterm fix.
+#undef  WINVER
+#define WINVER _WIN32_WINNT_WIN7
+#undef  _WIN32_WINNT
+#define _WIN32_WINNT _WIN32_WINNT_WIN7
+#include <windows.h>
+
 #include "chrome/browser/renderer_host/render_widget_host_view_win.h"
 
 #include <algorithm>
@@ -209,6 +217,14 @@
   return ::DefWindowProc(window, message, wparam, lparam);
 }
 
+// Must be dynamically loaded to avoid startup failures on Win XP.
+typedef BOOL (WINAPI *ChangeWindowMessageFilterExFunction)(
+    HWND hwnd,
+    UINT message,
+    DWORD action,
+    PCHANGEFILTERSTRUCT change_filter_struct);
+ChangeWindowMessageFilterExFunction g_ChangeWindowMessageFilterEx;
+
 }  // namespace
 
 // RenderWidgetHostView --------------------------------------------------------
@@ -446,12 +462,30 @@
   }
   DCHECK(window_class);
 
+  HWND orig_parent = ::GetParent(window);
   HWND parent = CreateWindowEx(
       WS_EX_LEFT | WS_EX_LTRREADING | WS_EX_RIGHTSCROLLBAR,
       MAKEINTATOM(window_class), 0,
       WS_CHILD | WS_CLIPCHILDREN | WS_CLIPSIBLINGS,
-      0, 0, 0, 0, ::GetParent(window), 0, GetModuleHandle(NULL), 0);
+      0, 0, 0, 0, orig_parent, 0, GetModuleHandle(NULL), 0);
   ui::CheckWindowCreated(parent);
+  // If UIPI is enabled we need to add message filters for parents with
+  // children that cross process boundaries.
+  if (::GetPropW(orig_parent, webkit::npapi::kNativeWindowClassFilterProp)) {
+    // Process-wide message filters required on Vista must be added to:
+    // chrome_content_client.cc ChromeContentClient::SandboxPlugin
+    if (!g_ChangeWindowMessageFilterEx) {
+      g_ChangeWindowMessageFilterEx =
+          reinterpret_cast<ChangeWindowMessageFilterExFunction>(
+              ::GetProcAddress(::GetModuleHandle(L"user32.dll"),
+                               "ChangeWindowMessageFilterEx"));
+    }
+    // Process-wide message filters required on Vista must be added to:
+    // chrome_content_client.cc ChromeContentClient::SandboxPlugin
+    g_ChangeWindowMessageFilterEx(parent, WM_MOUSEWHEEL, MSGFLT_ALLOW, NULL);
+    g_ChangeWindowMessageFilterEx(parent, WM_GESTURE, MSGFLT_ALLOW, NULL);
+    ::SetPropW(orig_parent, webkit::npapi::kNativeWindowClassFilterProp, NULL);

[jam, 2011/08/26 00:29:12]

this needs a matching call to RemoveProp(). per the SetProp msdn documentation:


Before a window is destroyed (that is, before it returns from processing the
WM_NCDESTROY message), an application must remove all entries it has added to
the property list. The application must use the RemoveProp function to remove
the entries. 

+  }
   ::SetParent(window, parent);
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,