Refine the unavailable plug-in indicator
https://bugs.webkit.org/show_bug.cgi?id=119400
<rdar://problem/14616012>

Reviewed by Oliver Hunt.

Add a border, flip the text and background colors, and make the indicator
much higher contrast, to be more visible on a variety of sites.
Also, refine the arrow to be less blocky and inlaid inside a circle.

* rendering/RenderEmbeddedObject.cpp:
(WebCore::replacementTextRoundedRectPressedColor):
(WebCore::replacementTextRoundedRectColor):
(WebCore::replacementTextColor):
(WebCore::unavailablePluginBorderColor):
(WebCore::drawReplacementArrow):
(WebCore::RenderEmbeddedObject::paintReplaced):
(WebCore::RenderEmbeddedObject::getReplacementTextGeometry):
(WebCore::RenderEmbeddedObject::unavailablePluginIndicatorBounds):
(WebCore::RenderEmbeddedObject::isInUnavailablePluginIndicator):
* rendering/RenderEmbeddedObject.h:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@153695 268f45cc-cd09-0410-ab3c-d52691b4dbfc