Support buttons attribute for drag event (chromium side).

content/browser/web_contents/web_contents_view_aura.cc

 // Copyright (c) 2012 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 "content/browser/web_contents/web_contents_view_aura.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/files/file_util.h"
 #include "base/metrics/histogram.h"
@@ skipping 440 matching lines @@
 int ConvertAuraEventFlagsToWebInputEventModifiers(int aura_event_flags) {
   int web_input_event_modifiers = 0;
   if (aura_event_flags & ui::EF_SHIFT_DOWN)
     web_input_event_modifiers |= blink::WebInputEvent::ShiftKey;
   if (aura_event_flags & ui::EF_CONTROL_DOWN)
     web_input_event_modifiers |= blink::WebInputEvent::ControlKey;
   if (aura_event_flags & ui::EF_ALT_DOWN)
     web_input_event_modifiers |= blink::WebInputEvent::AltKey;
   if (aura_event_flags & ui::EF_COMMAND_DOWN)
     web_input_event_modifiers |= blink::WebInputEvent::MetaKey;
+  if (aura_event_flags & ui::EF_LEFT_MOUSE_BUTTON)
+    web_input_event_modifiers |= blink::WebInputEvent::LeftButtonDown;
+  if (aura_event_flags & ui::EF_MIDDLE_MOUSE_BUTTON)
+    web_input_event_modifiers |= blink::WebInputEvent::MiddleButtonDown;
+  if (aura_event_flags & ui::EF_RIGHT_MOUSE_BUTTON)
+    web_input_event_modifiers |= blink::WebInputEvent::RightButtonDown;
   return web_input_event_modifiers;
 }
 
 }  // namespace
 
 class WebContentsViewAura::WindowObserver
     : public aura::WindowObserver, public aura::WindowTreeHostObserver {
  public:
   explicit WindowObserver(WebContentsViewAura* view)
       : view_(view),
@@ skipping 1166 matching lines @@
   if (visible) {
     if (!web_contents_->should_normally_be_visible())
       web_contents_->WasShown();
   } else {
     if (web_contents_->should_normally_be_visible())
       web_contents_->WasHidden();
   }
 }
 
 }  // namespace content