Revert of Revert "Only allow background tabs if the underlying input event allows it"

Source/web/FrameLoaderClientImpl.cpp

 /*
  * Copyright (C) 2009, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2011 Apple 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.
@@ skipping 448 matching lines @@
     if (m_webFrame->client())
         m_webFrame->client()->didFirstVisuallyNonEmptyLayout(m_webFrame);
 }
 
 void FrameLoaderClientImpl::dispatchDidChangeThemeColor()
 {
     if (m_webFrame->client())
         m_webFrame->client()->didChangeThemeColor();
 }
 
+static bool allowCreatingBackgroundTabs()
+{
+    const WebInputEvent* inputEvent = WebViewImpl::currentInputEvent();
+    if (!inputEvent || inputEvent->type != WebInputEvent::MouseUp)
+        return false;
+
+    const WebMouseEvent* mouseEvent = static_cast<const WebMouseEvent*>(inputEvent);
+
+    unsigned short buttonNumber;
+    switch (mouseEvent->button) {
+    case WebMouseEvent::ButtonLeft:
+        buttonNumber = 0;
+        break;
+    case WebMouseEvent::ButtonMiddle:
+        buttonNumber = 1;
+        break;
+    case WebMouseEvent::ButtonRight:
+        buttonNumber = 2;
+        break;
+    default:
+        return false;
+    }
+    bool ctrl = mouseEvent->modifiers & WebMouseEvent::ControlKey;
+    bool shift = mouseEvent->modifiers & WebMouseEvent::ShiftKey;
+    bool alt = mouseEvent->modifiers & WebMouseEvent::AltKey;
+    bool meta = mouseEvent->modifiers & WebMouseEvent::MetaKey;
+
+    NavigationPolicy userPolicy;
+    if (!navigationPolicyFromMouseEvent(buttonNumber, ctrl, shift, alt, meta, &userPolicy))
+        return false;
+    return userPolicy == NavigationPolicyNewBackgroundTab;
+}
+
 NavigationPolicy FrameLoaderClientImpl::decidePolicyForNavigation(const ResourceRequest& request, DocumentLoader* loader, NavigationPolicy policy, bool isTransitionNavigation)
 {
     if (!m_webFrame->client())
         return NavigationPolicyIgnore;
+
+    if (policy == NavigationPolicyNewBackgroundTab && !allowCreatingBackgroundTabs())
+        policy = NavigationPolicyNewForegroundTab;
+
     WebDataSourceImpl* ds = WebDataSourceImpl::fromDocumentLoader(loader);
 
     WrappedResourceRequest wrappedResourceRequest(request);
     WebFrameClient::NavigationPolicyInfo navigationInfo(wrappedResourceRequest);
     navigationInfo.frame = m_webFrame;
     navigationInfo.extraData = ds->extraData();
     navigationInfo.navigationType = ds->navigationType();
     navigationInfo.defaultPolicy = static_cast<WebNavigationPolicy>(policy);
     navigationInfo.isRedirect = ds->isRedirect();
     navigationInfo.isTransitionNavigation = isTransitionNavigation;
@@ skipping 406 matching lines @@
 
 unsigned FrameLoaderClientImpl::backForwardLength()
 {
     WebViewImpl* webview = m_webFrame->viewImpl();
     if (!webview || !webview->client())
         return 0;
     return webview->client()->historyBackListCount() + 1 + webview->client()->historyForwardListCount();
 }
 
 } // namespace blink