[chrome] Default the user-defined empty ctor and dtor where possible

I need an owner's approval please for changes under:
chrome/browser/ui/hung_renderer

This is a mechanical change. There are a few instances of empty
user-defined constructors and destructors left in the /chrome code
which can be defaulted.

This CL was uploaded by git cl split.

R=bsep@chromium.org

Bug: 381119547
Change-Id: I91b9978cb26acba8eea8856153822654b1f62027
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6056070
Reviewed-by: Peter Boström <pbos@chromium.org>
Commit-Queue: Sorin Jianu <sorin@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1389205}

chrome/browser/ui/hung_renderer/hung_renderer_interactive_uitest.cc

@@ -20,13 +20,13 @@
 
 class HungRendererNavigationTest : public InProcessBrowserTest {
  public:
-  HungRendererNavigationTest() {}
+  HungRendererNavigationTest() = default;
 
   HungRendererNavigationTest(const HungRendererNavigationTest&) = delete;
   HungRendererNavigationTest& operator=(const HungRendererNavigationTest&) =
       delete;
 
-  ~HungRendererNavigationTest() override {}
+  ~HungRendererNavigationTest() override = default;
 
  protected:
   void SetUpOnMainThread() override {