This fixes http://code.google.com/p/chromium/issues/detail?id=3007, which is ...

webkit/tools/test_shell/event_sending_controller.cc

 // Copyright (c) 2006-2008 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.
 
 // This file contains the definition for EventSendingController.
 //
 // Some notes about drag and drop handling:
 // Windows drag and drop goes through a system call to DoDragDrop.  At that
 // point, program control is given to Windows which then periodically makes
 // callbacks into the webview.  This won't work for layout tests, so instead,
@@ skipping 17 matching lines @@
 #include "webkit/tools/test_shell/test_shell.h"
 
 // TODO(mpcomplete): layout before each event?
 // TODO(mpcomplete): do we need modifiers for mouse events?
 
 TestShell* EventSendingController::shell_ = NULL;
 gfx::Point EventSendingController::last_mouse_pos_;
 WebMouseEvent::Button EventSendingController::pressed_button_ = 
     WebMouseEvent::BUTTON_NONE;
 
+int EventSendingController::last_button_number_ = -1;
+
 namespace {
 
 #if defined(OS_WIN)
 static scoped_refptr<IDataObject> drag_data_object;
 #elif defined(OS_MACOSX)
 // Throughout this file, drag support is #ifdef-ed out. TODO(port): Add it in
 // for the Mac.
 #endif
 static bool replaying_saved_events = false;
 static std::queue<WebMouseEvent> mouse_event_queue;
@@ skipping 94 matching lines @@
 void EventSendingController::Reset() {
   // The test should have finished a drag and the mouse button state.
 #if defined(OS_WIN)
   DCHECK(!drag_data_object);
   drag_data_object = NULL;
 #endif
   pressed_button_ = WebMouseEvent::BUTTON_NONE;
   dragMode.Set(true);
   last_click_time_sec = 0;
   click_count = 0;
+  last_button_number_ = -1;
 }
 
 /* static */ WebView* EventSendingController::webview() {
   return shell_->webView();
 }
 
 #if defined(OS_WIN)
 /* static */ void EventSendingController::DoDragDrop(IDataObject* data_obj) {
   drag_data_object = data_obj;
 
   DWORD effect = 0;
   POINTL screen_ptl = {0, 0};
   TestWebViewDelegate* delegate = shell_->delegate();
   delegate->drop_delegate()->DragEnter(drag_data_object, MK_LBUTTON,
                                        screen_ptl, &effect);
 
   // Finish processing events.
   ReplaySavedEvents();
 }
 #endif
 
-// static
-WebMouseEvent::Button EventSendingController::GetButtonTypeFromSingleArg(
-    const CppArgumentList& args) {
-  if (args.size() > 0 && args[0].isNumber()) {
-    int button_code = args[0].ToInt32();
-    if (button_code == 1)
-      return WebMouseEvent::BUTTON_MIDDLE;
-    else if (button_code == 2)
-      return WebMouseEvent::BUTTON_RIGHT;
-  }
-  return WebMouseEvent::BUTTON_LEFT;
+WebMouseEvent::Button EventSendingController::GetButtonTypeFromButtonNumber(
+    int button_code) {
+  if (button_code == 0)
+    return WebMouseEvent::BUTTON_LEFT;
+  else if (button_code == 2)
+    return WebMouseEvent::BUTTON_RIGHT;
+
+  return WebMouseEvent::BUTTON_MIDDLE;
 }
 
+// static
+int EventSendingController::GetButtonNumberFromSingleArg(
+    const CppArgumentList& args) {
+  int button_code = 0;
+
+  if (args.size() > 0 && args[0].isNumber()) {
+    button_code = args[0].ToInt32();
+  }
+
+  return button_code;
+}
 //
 // Implemented javascript methods.
 //
 
  void EventSendingController::mouseDown(
     const CppArgumentList& args, CppVariant* result) {
   result->SetNull();
 
   webview()->Layout();
 
-  WebMouseEvent::Button button_type = GetButtonTypeFromSingleArg(args);
+  int button_number = GetButtonNumberFromSingleArg(args);
+  DCHECK(button_number != -1);
 
-  if ((GetCurrentEventTimeSec() - last_click_time_sec >= kMultiClickTimeSec) ||
-      outside_multiclick_radius(last_mouse_pos_, last_click_pos)) {
+  WebMouseEvent::Button button_type = GetButtonTypeFromButtonNumber(
+      button_number);
+
+  if ((GetCurrentEventTimeSec() - last_click_time_sec < kMultiClickTimeSec) &&
+      (!outside_multiclick_radius(last_mouse_pos_, last_click_pos)) &&
+      (button_number == last_button_number_)) {
+    ++click_count;
+  } else {
     click_count = 1;
-  } else {
-    ++click_count;
   }
 
+  last_button_number_ = button_number;
+
   WebMouseEvent event;
   pressed_button_ = button_type;
   InitMouseEvent(WebInputEvent::MOUSE_DOWN, button_type,
                  last_mouse_pos_, &event);
   webview()->HandleInputEvent(&event);
 }
 
  void EventSendingController::mouseUp(
     const CppArgumentList& args, CppVariant* result) {
   result->SetNull();
 
   webview()->Layout();
 
-  WebMouseEvent::Button button_type = GetButtonTypeFromSingleArg(args);
+  int button_number = GetButtonNumberFromSingleArg(args);
+  DCHECK(button_number != -1);
+
+  WebMouseEvent::Button button_type = GetButtonTypeFromButtonNumber(
+      button_number);
+
+  last_button_number_ = button_number;
 
   WebMouseEvent event;
   InitMouseEvent(WebInputEvent::MOUSE_UP, button_type,
                  last_mouse_pos_, &event);
   if (drag_mode() && !replaying_saved_events) {
     mouse_event_queue.push(event);
     ReplaySavedEvents();
   } else {
     DoMouseUp(event);
   }
@@ skipping 313 matching lines @@
  void EventSendingController::fireKeyboardEventsToElement(
     const CppArgumentList& args, CppVariant* result) {
   result->SetNull();
 }
 
  void EventSendingController::clearKillRing(
     const CppArgumentList& args, CppVariant* result) {
   result->SetNull();
 }