diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp
index d2b6634105800..c4a78da25438b 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp
@@ -192,8 +192,9 @@ bool isPtrConversion(const FunctionDecl *F) {
   // FIXME: check # of params == 1
   const auto FunctionName = safeGetName(F);
   if (FunctionName == "getPtr" || FunctionName == "WeakPtr" ||
-      FunctionName == "dynamicDowncast"
-      || FunctionName == "downcast" || FunctionName == "bitwise_cast")
+      FunctionName == "dynamicDowncast" || FunctionName == "downcast" ||
+      FunctionName == "checkedDowncast" ||
+      FunctionName == "uncheckedDowncast" || FunctionName == "bitwise_cast")
     return true;
 
   return false;
diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp
index 31ccae8b097b8..cc4585a0b0eef 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp
@@ -148,13 +148,14 @@ class UncountedCallArgsChecker
 
     auto name = safeGetName(Callee);
     if (name == "adoptRef" || name == "getPtr" || name == "WeakPtr" ||
-        name == "dynamicDowncast" || name == "downcast" || name == "bitwise_cast" ||
-        name == "is" || name == "equal" || name == "hash" ||
-        name == "isType"
+        name == "dynamicDowncast" || name == "downcast" ||
+        name == "checkedDowncast" || name == "uncheckedDowncast" ||
+        name == "bitwise_cast" || name == "is" || name == "equal" ||
+        name == "hash" || name == "isType" ||
         // FIXME: Most/all of these should be implemented via attributes.
-        || name == "equalIgnoringASCIICase" ||
+        name == "equalIgnoringASCIICase" ||
         name == "equalIgnoringASCIICaseCommon" ||
-        name == "equalIgnoringNullity")
+        name == "equalIgnoringNullity" || name == "toString")
       return true;
 
     return false;
diff --git a/clang/test/Analysis/Checkers/WebKit/call-args-dynamic-downcast.cpp b/clang/test/Analysis/Checkers/WebKit/call-args-safe-functions.cpp
similarity index 55%
rename from clang/test/Analysis/Checkers/WebKit/call-args-dynamic-downcast.cpp
rename to clang/test/Analysis/Checkers/WebKit/call-args-safe-functions.cpp
index 28156623d9a0f..a87446564870c 100644
--- a/clang/test/Analysis/Checkers/WebKit/call-args-dynamic-downcast.cpp
+++ b/clang/test/Analysis/Checkers/WebKit/call-args-safe-functions.cpp
@@ -23,13 +23,34 @@ class OtherObject {
     Derived* obj();
 };
 
+class String {
+};
+
 template<typename Target, typename Source>
 inline Target* dynamicDowncast(Source* source)
 {
     return static_cast<Target*>(source);
 }
 
+template<typename Target, typename Source>
+inline Target* checkedDowncast(Source* source)
+{
+    return static_cast<Target*>(source);
+}
+
+template<typename Target, typename Source>
+inline Target* uncheckedDowncast(Source* source)
+{
+    return static_cast<Target*>(source);
+}
+
+template<typename... Types>
+String toString(const Types&... values);
+
 void foo(OtherObject* other)
 {
     dynamicDowncast<SubDerived>(other->obj());
+    checkedDowncast<SubDerived>(other->obj());
+    uncheckedDowncast<SubDerived>(other->obj());
+    toString(other->obj());
 }