Add scheme exceptions for isSecureContext

third_party/WebKit/Source/core/dom/Document.cpp

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index 9fa9677b4fb48e5ff88842ea7e039a5f757dd04e..cdd32165c7af4eb85d41be6f54d4f3e3688f1d54 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -5667,12 +5667,45 @@ v8::Local<v8::Object> Document::associateWithWrapper(v8::Isolate* isolate, const
 
 bool Document::isSecureContext(String& errorMessage, const SecureContextCheck privilegeContextCheck) const
 {
+    // There may be exceptions for the secure context check defined for certain
+    // schemes. The exceptions are applied only to the special scheme and to
+    // sandboxed URLs from those origins, but *not* to any children.
+    //
+    // For example:
+    //   <iframe src="http://host">
+    //     <iframe src="scheme-has-exception://host"></iframe>
+    //     <iframe sandbox src="scheme-has-exception://host"></iframe>
+    //   </iframe>
+    // both inner iframes pass this check, assuming that the scheme
+    // "scheme-has-exception:" is granted an exception.
+    //
+    // However,
+    //   <iframe src="http://host">
+    //     <iframe sandbox src="http://host"></iframe>
+    //   </iframe>
+    // would fail the check (that is, sandbox does not grant an exception itself).
+    //
+    // Additionally, with
+    //   <iframe src="scheme-has-exception://host">
+    //     <iframe src="http://host"></iframe>
+    //     <iframe sandbox src="http://host"></iframe>
+    //   </iframe>
+    // both inner iframes would fail the check, even though the outermost iframe
+    // passes.
+    //
+    // In all cases, a frame must be potentially trustworthy in addition to
+    // having an exception listed in order for the exception to be granted.
     if (SecurityContext::isSandboxed(SandboxOrigin)) {
-        if (!SecurityOrigin::create(url())->isPotentiallyTrustworthy(errorMessage))
+        RefPtr<SecurityOrigin> origin = SecurityOrigin::create(url());
+        if (!origin->isPotentiallyTrustworthy(errorMessage))
             return false;
+        if (SchemeRegistry::schemeShouldBypassSecureContextCheck(origin->protocol()))
+            return true;
     } else {
         if (!securityOrigin()->isPotentiallyTrustworthy(errorMessage))
             return false;
+        if (SchemeRegistry::schemeShouldBypassSecureContextCheck(securityOrigin()->protocol()))
+            return true;
     }
 
     if (privilegeContextCheck == StandardSecureContextCheck) {