Revert r154797: "Move isValid/isCurrentColor from Color to StyleColor"

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index 801fc8e469e17063a06f51af349e03f94e4c8c4d..4f339f84294c5ae82e6e92181630343971a3693a 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -1242,7 +1242,7 @@ void WebViewImpl::enableTapHighlight(const PlatformGestureEvent& tapEvent)
     if (!touchNode || !touchNode->renderer() || !touchNode->renderer()->enclosingLayer())
         return;
 
-    Color highlightColor = touchNode->renderer()->resolveColor(CSSPropertyWebkitTapHighlightColor);
+    Color highlightColor = touchNode->renderer()->style()->tapHighlightColor();
     // Safari documentation for -webkit-tap-highlight-color says if the specified color has 0 alpha,
     // then tap highlighting is disabled.
     // http://developer.apple.com/library/safari/#documentation/appleapplications/reference/safaricssref/articles/standardcssproperties.html
@@ -2407,7 +2407,7 @@ WebColor WebViewImpl::backgroundColor() const
     if (!m_page)
         return m_baseBackgroundColor;
     FrameView* view = m_page->mainFrame()->view();
-    StyleColor backgroundColor = view->documentBackgroundColor();
+    Color backgroundColor = view->documentBackgroundColor();
     if (!backgroundColor.isValid())
         return m_baseBackgroundColor;
     return backgroundColor.rgb();