Add scroll and gesture message filters for UIPI Flash.

content/browser/plugin_process_host.cc

Index: content/browser/plugin_process_host.cc
===================================================================
--- content/browser/plugin_process_host.cc	(revision 96873)
+++ content/browser/plugin_process_host.cc	(working copy)
@@ -45,6 +45,8 @@
 #endif
 
 #if defined(OS_WIN)
+#include "base/win/windows_version.h"
+#include "webkit/plugins/npapi/plugin_constants_win.h"
 #include "webkit/plugins/npapi/webplugin_delegate_impl.h"
 
 namespace {
@@ -58,6 +60,9 @@
 
   ::SetWindowLongPtr(window, GWL_STYLE, window_style);
   ::SetParent(window, parent);
+  // Allow the Flash plugin to forward some messages back to Chrome.
+  if (base::win::GetVersion() >= base::win::VERSION_WIN7)
+    ::SetPropW(parent, webkit::npapi::kNativeWindowClassFilterProp, HANDLE(-1));
 }
 
 }  // namespace
@@ -79,8 +84,11 @@
 }
 
 void PluginProcessHost::OnReparentPluginWindow(HWND window, HWND parent) {
-  // Reparent only to our process.
+  // Reparent only from the plugin process to our process.
   DWORD process_id = 0;
+  ::GetWindowThreadProcessId(window, &process_id);
+  if (process_id != ::GetProcessId(GetChildProcessHandle()))
+    return;
   ::GetWindowThreadProcessId(parent, &process_id);
   if (process_id != ::GetCurrentProcessId())
     return;