Allows adding trusted certs on iOS.

runtime/bin/secure_socket_macos.h

Index: runtime/bin/secure_socket_macos.h
diff --git a/runtime/bin/secure_socket_macos.h b/runtime/bin/secure_socket_macos.h
index e78321cda96a4c86d98eaff139ac7a570dfb0b9e..c088d8c7e84d8730a3a2850a7069b4e9510d5379 100644
--- a/runtime/bin/secure_socket_macos.h
+++ b/runtime/bin/secure_socket_macos.h
@@ -143,6 +143,64 @@ class SSLFilter {
   DISALLOW_COPY_AND_ASSIGN(SSLFilter);
 };
 
+// Where the argument to the constructor is the handle for an object
+// implementing List<int>, this class creates a scope in which the memory
+// backing the list can be accessed.
+//
+// Do not make Dart_ API calls while in a ScopedMemBuffer.
+// Do not call Dart_PropagateError while in a ScopedMemBuffer.
+class ScopedMemBuffer {
+ public:
+  explicit ScopedMemBuffer(Dart_Handle object) {
+    if (!Dart_IsTypedData(object) && !Dart_IsList(object)) {
+      Dart_ThrowException(DartUtils::NewDartArgumentError(
+          "Argument is not a List<int>"));
+    }
+
+    uint8_t* bytes = NULL;
+    intptr_t bytes_len = 0;
+    bool is_typed_data = false;
+    if (Dart_IsTypedData(object)) {
+      is_typed_data = true;
+      Dart_TypedData_Type typ;
+      ThrowIfError(Dart_TypedDataAcquireData(
+          object,
+          &typ,
+          reinterpret_cast<void**>(&bytes),
+          &bytes_len));
+    } else {
+      ASSERT(Dart_IsList(object));
+      ThrowIfError(Dart_ListLength(object, &bytes_len));
+      bytes = Dart_ScopeAllocate(bytes_len);
+      ASSERT(bytes != NULL);
+      ThrowIfError(Dart_ListGetAsBytes(object, 0, bytes, bytes_len));
+    }
+
+    object_ = object;
+    bytes_ = bytes;
+    bytes_len_ = bytes_len;
+    is_typed_data_ = is_typed_data;
+  }
+
+  ~ScopedMemBuffer() {
+    if (is_typed_data_) {
+      ThrowIfError(Dart_TypedDataReleaseData(object_));
+    }
+  }
+
+  uint8_t* get() const { return bytes_; }
+  intptr_t length() const { return bytes_len_; }
+
+ private:
+  Dart_Handle object_;
+  uint8_t* bytes_;
+  intptr_t bytes_len_;
+  bool is_typed_data_;
+
+  DISALLOW_ALLOCATION();
+  DISALLOW_COPY_AND_ASSIGN(ScopedMemBuffer);
+};
+
 }  // namespace bin
 }  // namespace dart