Move plugin placeholder style to CSS, and allow it to bypass main world CSP.

Source/bindings/core/v8/ScriptController.cpp

Index: Source/bindings/core/v8/ScriptController.cpp
diff --git a/Source/bindings/core/v8/ScriptController.cpp b/Source/bindings/core/v8/ScriptController.cpp
index 30482004680d0ffe285856ea4f2d91cca0fb404e..f4c8860f065ead18c124d5a2eac325f4d26dc22b 100644
--- a/Source/bindings/core/v8/ScriptController.cpp
+++ b/Source/bindings/core/v8/ScriptController.cpp
@@ -96,6 +96,7 @@ ScriptController::ScriptController(LocalFrame* frame)
     , m_isolate(v8::Isolate::GetCurrent())
     , m_windowProxy(WindowProxy::create(frame, DOMWrapperWorld::mainWorld(), m_isolate))
     , m_windowScriptNPObject(0)
+    , m_bypassMainWorldCSP(false)
 {
 }
 
@@ -240,6 +241,9 @@ WindowProxy* ScriptController::windowProxy(DOMWrapperWorld& world)
 
 bool ScriptController::shouldBypassMainWorldCSP()
 {
+    if (m_bypassMainWorldCSP)
+        return true;
+
     v8::Handle<v8::Context> context = m_isolate->GetCurrentContext();
     if (context.IsEmpty() || !toDOMWindow(context))
         return false;