Add "lax mixed content checking" runtime flag.

Source/core/loader/MixedContentChecker.cpp

Index: Source/core/loader/MixedContentChecker.cpp
diff --git a/Source/core/loader/MixedContentChecker.cpp b/Source/core/loader/MixedContentChecker.cpp
index 75e9737cd51391e37494c5be4b2107897335b82e..ea95015d1ed244d8e5e552adb375226b0c076c28 100644
--- a/Source/core/loader/MixedContentChecker.cpp
+++ b/Source/core/loader/MixedContentChecker.cpp
@@ -34,6 +34,7 @@
 #include "core/frame/Settings.h"
 #include "core/loader/FrameLoader.h"
 #include "core/loader/FrameLoaderClient.h"
+#include "platform/RuntimeEnabledFeatures.h"
 #include "platform/weborigin/SecurityOrigin.h"
 #include "wtf/text/StringBuilder.h"
 
@@ -90,6 +91,13 @@ bool MixedContentChecker::canRunInsecureContentInternal(SecurityOrigin* security
     return allowed;
 }
 
+bool MixedContentChecker::canConnectInsecureWebSocket(SecurityOrigin* securityOrigin, const KURL& url) const
+{
+    if (RuntimeEnabledFeatures::laxMixedContentCheckingEnabled())
+        return canDisplayInsecureContentInternal(securityOrigin, url, MixedContentChecker::WebSocket);
+    return canRunInsecureContentInternal(securityOrigin, url, MixedContentChecker::WebSocket);
+}
+
 void MixedContentChecker::logWarning(bool allowed, const KURL& target, const MixedContentType type) const
 {
     StringBuilder message;