Add support for touch based zoom gesture on Windows. This change also handles the WM_POINTERDOWN

content/browser/renderer_host/render_widget_host_view_win.h

Index: content/browser/renderer_host/render_widget_host_view_win.h
===================================================================
--- content/browser/renderer_host/render_widget_host_view_win.h	(revision 107928)
+++ content/browser/renderer_host/render_widget_host_view_win.h	(working copy)
@@ -50,6 +50,21 @@
 
 CONTENT_EXPORT extern const wchar_t kRenderWidgetHostHWNDClass[];
 
+// TODO(ananta)
+// This should be removed once we have the new windows SDK which defines these
+// messages.
+#if !defined(WM_POINTERUPDATE)
+#define WM_POINTERUPDATE 0x0245
+#endif  // WM_POINTERUPDATE
+
+#if !defined(WM_POINTERDOWN)
+#define WM_POINTERDOWN  0x0246
+#endif  // WM_POINTERDOWN
+
+#if !defined(WM_POINTERUP)
+#define WM_POINTERUP    0x0247
+#endif  // WM_POINTERUP
+
 ///////////////////////////////////////////////////////////////////////////////
 // RenderWidgetHostViewWin
 //
@@ -129,6 +144,8 @@
     MESSAGE_HANDLER(WM_MOUSEACTIVATE, OnMouseActivate)
     MESSAGE_HANDLER(WM_GETOBJECT, OnGetObject)
     MESSAGE_HANDLER(WM_PARENTNOTIFY, OnParentNotify)
+    MESSAGE_HANDLER(WM_POINTERDOWN, OnPointerMessage)
+    MESSAGE_HANDLER(WM_POINTERUP, OnPointerMessage)
     MESSAGE_HANDLER(WM_GESTURE, OnGestureEvent)
   END_MSG_MAP()
 
@@ -240,6 +257,10 @@
 
   LRESULT OnParentNotify(UINT message, WPARAM wparam, LPARAM lparam,
                          BOOL& handled);
+
+  // Handle the new pointer messages
+  LRESULT OnPointerMessage(UINT message, WPARAM wparam, LPARAM lparam,
+                           BOOL& handled);
   // Handle high-level touch events.
   LRESULT OnGestureEvent(UINT message, WPARAM wparam, LPARAM lparam,
                          BOOL& handled);
@@ -411,6 +432,14 @@
   // back, we regard the mouse movement as (0, 0).
   bool ignore_mouse_movement_;
 
+  // Set to true if the next lbutton down message is to be ignored. Set by the
+  // WM_POINTERXX handler. We do this to ensure that we don't send out
+  // duplicate lbutton down messages to the renderer.
+  bool ignore_next_lbutton_message_at_same_location;
+  // The location of the last WM_POINTERDOWN message. We ignore the subsequent
+  // lbutton down only if the locations match.
+  LPARAM last_pointer_down_location_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewWin);
 };