Blink Plugins: Remove Shadow DOM Plugin Placeholder

Source/core/dom/StyleElement.cpp

Index: Source/core/dom/StyleElement.cpp
diff --git a/Source/core/dom/StyleElement.cpp b/Source/core/dom/StyleElement.cpp
index d7303a3bb7e73c5d84cf13a8eb6a7d8feffbde95..7d18e36ba2362822d74cd43cb58efa2cab3c26b1 100644
--- a/Source/core/dom/StyleElement.cpp
+++ b/Source/core/dom/StyleElement.cpp
@@ -156,29 +156,19 @@ void StyleElement::clearSheet(Element* ownerElement)
     m_sheet.release()->clearOwnerNode();
 }
 
-static bool shouldBypassMainWorldCSP(Element* element)
-{
-    // Main world CSP is bypassed within an isolated world.
-    LocalFrame* frame = element->document().frame();
-    if (frame && frame->script().shouldBypassMainWorldCSP())
-        return true;
-
-    // Main world CSP is bypassed for style elements in user agent shadow DOM.
-    ShadowRoot* root = element->containingShadowRoot();
-    if (root && root->type() == ShadowRootType::UserAgent)
-        return true;
-
-    return false;
-}
-
 StyleElement::ProcessingResult StyleElement::createSheet(Element* e, const String& text)
 {
     ASSERT(e);
     ASSERT(e->inDocument());
     Document& document = e->document();
 
+    // Inline style added from an isolated world should bypass the main world's
+    // CSP just as an inline script would.
+    LocalFrame* frame = document.frame();
+    bool shouldBypassMainWorldCSP = frame && frame->script().shouldBypassMainWorldCSP();

[tommycli, 2015/08/25 00:18:10]

Needs extra scrutiny. Your patch added the shadow dom STYLE CSP exemption. Do we
still need it?

[jbroman, 2015/08/25 00:34:10]

I'm not aware of any other users (but can't actually rule out any being added).
If nothing breaks, it's probably OK.

[jbroman, 2015/08/25 13:57:21]

FYI: I just got reminded of
https://code.google.com/p/chromium/issues/detail?id=424613 (which I filed, so I
ought to have remembered). It's possible that <marquee> may be relying, or may
start relying, on this, if it wants its CSS to work on CSP-restricted pages. (An
edge case, though, to be sure.)

This might be a reason to leave this logic intact.

[tommycli, 2015/08/25 16:48:17]

Done. I'll leave it intact.

+
     const ContentSecurityPolicy* csp = document.contentSecurityPolicy();
-    bool passesContentSecurityPolicyChecks = shouldBypassMainWorldCSP(e)
+    bool passesContentSecurityPolicyChecks = shouldBypassMainWorldCSP
         || csp->allowStyleWithHash(text)
         || csp->allowStyleWithNonce(e->fastGetAttribute(HTMLNames::nonceAttr))
         || csp->allowInlineStyle(e->document().url(), m_startPosition.m_line, text);