Fix defaulted comparisons to follow best practices/style guide

I wrote these somewhat incorrectly in https://crrev.com/c/6175640.

See https://docs.google.com/presentation/d/13VxKq7L-vY4mPVnK7NMMEMjfAuoDfj3SFcZbW01z3HM/edit#slide=id.g3290701ab79_0_44

Change-Id: Ie3a0e678ac2cbb29845abd0a2dc4e17c5037bd72
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6309755
Reviewed-by: Charlie Harrison <csharrison@chromium.org>
Commit-Queue: Maks Orlovich <morlovich@chromium.org>
Auto-Submit: Chris Fredrickson <cfredric@chromium.org>
Reviewed-by: Maks Orlovich <morlovich@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1425830}

net/base/schemeful_site.h

@@ -149,7 +149,10 @@ class NET_EXPORT SchemefulSite {
   // See base/trace_event/memory_usage_estimator.h for more info.
   size_t EstimateMemoryUsage() const;
 
-  std::strong_ordering operator<=>(const SchemefulSite& other) const = default;
+  friend bool operator==(const SchemefulSite& left,
+                         const SchemefulSite& right) = default;
+  friend auto operator<=>(const SchemefulSite& left,
+                          const SchemefulSite& right) = default;
 
  private:
   // IPC serialization code needs to access internal origin.

net/cookies/unique_cookie_key.h

@@ -64,8 +64,10 @@ class NET_EXPORT UniqueCookieKey {
 
   ~UniqueCookieKey();
 
-  std::strong_ordering operator<=>(const UniqueCookieKey& other) const =
-      default;
+  friend bool operator==(const UniqueCookieKey& left,
+                         const UniqueCookieKey& right) = default;
+  friend auto operator<=>(const UniqueCookieKey& left,
+                          const UniqueCookieKey& right) = default;
 
   const std::string& name() const { return name_; }
   const std::string& domain() const { return domain_; }

url/origin.h

@@ -282,7 +282,8 @@ class COMPONENT_EXPORT(URL) Origin {
 
   // Allows Origin to be used as a key in STL (for example, a std::set or
   // std::map).
-  std::strong_ordering operator<=>(const Origin& other) const = default;
+  friend bool operator==(const Origin& left, const Origin& right) = default;
+  friend auto operator<=>(const Origin& left, const Origin& right) = default;
 
   // Creates a new opaque origin that is guaranteed to be cross-origin to all
   // currently existing origins. An origin created by this method retains its

url/scheme_host_port.cc

@@ -269,11 +269,6 @@ size_t SchemeHostPort::EstimateMemoryUsage() const {
          base::trace_event::EstimateMemoryUsage(host_);
 }
 
-bool SchemeHostPort::operator==(const SchemeHostPort& other) const = default;
-
-std::strong_ordering SchemeHostPort::operator<=>(
-    const SchemeHostPort& other) const = default;
-
 std::string SchemeHostPort::SerializeInternal(url::Parsed* parsed) const {
   std::string result;
   if (!IsValid())

url/scheme_host_port.h

@@ -148,8 +148,10 @@ class COMPONENT_EXPORT(URL) SchemeHostPort {
   // Note that this comparison is _not_ the same as an origin-based comparison.
   // In particular, invalid SchemeHostPort objects match each other (and
   // themselves). Opaque origins, on the other hand, would not.
-  bool operator==(const SchemeHostPort& other) const;
-  std::strong_ordering operator<=>(const SchemeHostPort& other) const;
+  friend bool operator==(const SchemeHostPort& left,
+                         const SchemeHostPort& right) = default;
+  friend auto operator<=>(const SchemeHostPort& left,
+                          const SchemeHostPort& right) = default;
 
   // Whether to discard host and port information for a specific scheme.
   //