Add missing virtual/protected destructor definitions on virtual classes

Change-Id: Ic12e131e3e23d153dd5c9733d8f8c5062adbf802
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/2259334
Commit-Queue: Eric Astor <epastor@google.com>
Reviewed-by: Mark Mentovai <mark@chromium.org>
diff --git a/client/crashpad_client_linux.cc b/client/crashpad_client_linux.cc
index 9e5141f..4fb99d8 100644
--- a/client/crashpad_client_linux.cc
+++ b/client/crashpad_client_linux.cc
@@ -164,6 +164,7 @@
 
  protected:
   SignalHandler() = default;
+  ~SignalHandler() = default;
 
   bool Install(const std::set<int>* unhandled_signals) {
     DCHECK(!handler_);
diff --git a/tools/mac/catch_exception_tool.cc b/tools/mac/catch_exception_tool.cc
index 4f40372..06fda23 100644
--- a/tools/mac/catch_exception_tool.cc
+++ b/tools/mac/catch_exception_tool.cc
@@ -51,7 +51,7 @@
   MachMessageServer::Persistent persistent;
 };
 
-class ExceptionServer : public UniversalMachExcServer::Interface {
+class ExceptionServer final : public UniversalMachExcServer::Interface {
  public:
   ExceptionServer(const Options& options,
                   const std::string& me,