Support buttons attribute for drag event (blink side).

Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 215 matching lines @@
 STATIC_ASSERT_MATCHING_ENUM(DragOperationCopy);
 STATIC_ASSERT_MATCHING_ENUM(DragOperationLink);
 STATIC_ASSERT_MATCHING_ENUM(DragOperationGeneric);
 STATIC_ASSERT_MATCHING_ENUM(DragOperationPrivate);
 STATIC_ASSERT_MATCHING_ENUM(DragOperationMove);
 STATIC_ASSERT_MATCHING_ENUM(DragOperationDelete);
 STATIC_ASSERT_MATCHING_ENUM(DragOperationEvery);
 
 static bool shouldUseExternalPopupMenus = false;
 
 static int webInputEventKeyStateToPlatformEventKeyState(int webInputEventKeyState)

[Rick Byers, 2015/02/04 11:42:34]

This function is redundant with WebInputEventConversion's 
toPlatformMouseEventModifiers function, can you unify them (eg. expose that
function and delete this one)?

Also "key state" is now a poor name for the field in the DragData since it's
really platform mouse event modifiers.  Can you please rename it if it's not too
much trouble?

[zino, 2015/02/06 07:00:40]

Done.

 {
     int platformEventKeyState = 0;
     if (webInputEventKeyState & WebInputEvent::ShiftKey)
         platformEventKeyState = platformEventKeyState | PlatformEvent::ShiftKey;
     if (webInputEventKeyState & WebInputEvent::ControlKey)
         platformEventKeyState = platformEventKeyState | PlatformEvent::CtrlKey;
     if (webInputEventKeyState & WebInputEvent::AltKey)
         platformEventKeyState = platformEventKeyState | PlatformEvent::AltKey;
     if (webInputEventKeyState & WebInputEvent::MetaKey)
         platformEventKeyState = platformEventKeyState | PlatformEvent::MetaKey;
+    if (webInputEventKeyState & WebInputEvent::LeftButtonDown)
+        platformEventKeyState = platformEventKeyState | PlatformEvent::LeftButtonDown;
+    if (webInputEventKeyState & WebInputEvent::MiddleButtonDown)
+        platformEventKeyState = platformEventKeyState | PlatformEvent::MiddleButtonDown;
+    if (webInputEventKeyState & WebInputEvent::RightButtonDown)
+        platformEventKeyState = platformEventKeyState | PlatformEvent::RightButtonDown;
     return platformEventKeyState;
 }
 
 namespace {
 
 class UserGestureNotifier {
 public:
     // If a UserGestureIndicator is created for a user gesture since the last
     // page load and *userGestureObserved is false, the UserGestureNotifier
     // will notify the client and set *userGestureObserved to true.
@@ skipping 4349 matching lines @@
     return mainFrameImpl()->frameView()->layoutSize().width() == m_size.width
         || (constraints.minimumScale == constraints.maximumScale && constraints.minimumScale != -1);
 }
 
 void WebViewImpl::forceNextWebGLContextCreationToFail()
 {
     WebGLRenderingContext::forceNextWebGLContextCreationToFail();
 }
 
 } // namespace blink