Lands http://codereview.chromium.org/159838 for Pierre-Antoine. From him:...

views/controls/button/button_dropdown.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.
 
 #include "views/controls/button/button_dropdown.h"
 
 #include "app/l10n_util.h"
 #include "base/compiler_specific.h"
 #include "base/message_loop.h"
 #include "grit/app_strings.h"
@@ skipping 34 matching lines @@
     // determine if the user dragged the mouse down (which should pop up the
     // drag down menu immediately, instead of waiting for the timer)
     y_position_on_lbuttondown_ = e.y();
 
     // Schedule a task that will show the menu.
     MessageLoop::current()->PostDelayedTask(FROM_HERE,
         show_menu_factory_.NewRunnableMethod(&ButtonDropDown::ShowDropDownMenu,
                                              GetWidget()->GetNativeView()),
         kMenuTimerDelay);
   }
-
   return ImageButton::OnMousePressed(e);
 }
 
 void ButtonDropDown::OnMouseReleased(const MouseEvent& e, bool canceled) {
-  ImageButton::OnMouseReleased(e, canceled);
+  if (e.IsLeftMouseButton() || (e.IsRightMouseButton() &&
+                                !HitTest(e.location()))) {
+    ImageButton::OnMouseReleased(e, canceled);
+  }
 
   if (canceled)
     return;
 
   if (e.IsLeftMouseButton())
     show_menu_factory_.RevokeAll();
 
   if (IsEnabled() && e.IsRightMouseButton() && HitTest(e.location())) {
     show_menu_factory_.RevokeAll();
-    // Make the button look depressed while the menu is open.
-    // NOTE: SetState() schedules a paint, but it won't occur until after the
-    //       context menu message loop has terminated, so we PaintNow() to
-    //       update the appearance synchronously.
-    SetState(BS_PUSHED);
-    PaintNow();
     ShowDropDownMenu(GetWidget()->GetNativeView());
+    // Set the state back to normal after the drop down menu is closed.
+    if (state_ != BS_DISABLED)
+      SetState(BS_NORMAL);
   }
 }
 
 bool ButtonDropDown::OnMouseDragged(const MouseEvent& e) {
   bool result = ImageButton::OnMouseDragged(e);
 
   if (!show_menu_factory_.empty()) {
     // If the mouse is dragged to a y position lower than where it was when
     // clicked then we should not wait for the menu to appear but show
     // it immediately.
     if (e.y() > y_position_on_lbuttondown_ + GetHorizontalDragThreshold()) {
       show_menu_factory_.RevokeAll();
       ShowDropDownMenu(GetWidget()->GetNativeView());
     }
   }
 
   return result;
 }
 
+void ButtonDropDown::OnMouseExited(const MouseEvent& e) {
+  // Starting a drag results in a MouseExited, we need to ignore it.
+  // A right click release triggers an exit event. We want to
+  // remain in a PUSHED state until the drop down menu closes.
+  if (state_ != BS_DISABLED && !InDrag() && state_ != BS_PUSHED)
+    SetState(BS_NORMAL);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 //
 // ButtonDropDown - Menu functions
 //
 ////////////////////////////////////////////////////////////////////////////////
 
 void ButtonDropDown::ShowContextMenu(int x, int y, bool is_mouse_gesture) {
   show_menu_factory_.RevokeAll();
   // Make the button look depressed while the menu is open.
   // NOTE: SetState() schedules a paint, but it won't occur until after the
   //       context menu message loop has terminated, so we PaintNow() to
   //       update the appearance synchronously.
   SetState(BS_PUSHED);
   PaintNow();
   ShowDropDownMenu(GetWidget()->GetNativeView());
   SetState(BS_HOT);
 }
 
+bool ButtonDropDown::ShouldEnterPushedState(const MouseEvent& e) {
+  // Enter PUSHED state on press with Left or Right mouse button. Remain
+  // in this state while the context menu is open.
+  return ((MouseEvent::EF_LEFT_BUTTON_DOWN |
+    MouseEvent::EF_RIGHT_BUTTON_DOWN) & e.GetFlags()) != 0;
+}
+
 void ButtonDropDown::ShowDropDownMenu(gfx::NativeView window) {
   if (model_) {
     gfx::Rect lb = GetLocalBounds(true);
 
     // Both the menu position and the menu anchor type change if the UI layout
     // is right-to-left.
     gfx::Point menu_position(lb.origin());
     menu_position.Offset(0, lb.height() - 1);
     if (UILayoutIsRightToLeft())
       menu_position.Offset(lb.width() - 1, 0);
@@ skipping 43 matching lines @@
 }
 
 bool ButtonDropDown::GetAccessibleState(AccessibilityTypes::State* state) {
   DCHECK(state);
 
   *state = AccessibilityTypes::STATE_HASPOPUP;
   return true;
 }
 
 }  // namespace views