Remove DefaultHash<scoped_refptr<const SecurityOrigin>>.

The existance of this DefaultHash implementation is potentially problematic
for several reasons:

- DefaultHash<scoped_refptr<T>> exists as well, making it very easy to end up
  with ODR violations where different translation units end up with different
  types for a HashSet<scoped_refptr<const SecurityOrigin>>.
- It is not obvious what "equality" the hash implements, since there are at
  least two equally valid definitions of equality for origins ("same origin"
  vs "same origin-domain").

Currently no code is actually using this hash, but our upcoming DOMStorage
onion souping will want a hash that implements same origin equality, so
for that this also changes the implementation to implement that version of
equality.

Bug: 781870
Change-Id: I79d8820194b51cb81ba4bf0684e65cba575dba82
Reviewed-on: https://chromium-review.googlesource.com/1229357Reviewed-by: Daniel Murphy <dmurph@chromium.org>
Reviewed-by: Mike West <mkwst@chromium.org>
Commit-Queue: Marijn Kruisselbrink <mek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#592536}

third_party/blink/renderer/modules/webdatabase/database_tracker.cc

@@ -46,7 +46,6 @@
 #include "third_party/blink/renderer/modules/webdatabase/sqlite/sqlite_file_system.h"
 #include "third_party/blink/renderer/platform/cross_thread_functional.h"
 #include "third_party/blink/renderer/platform/weborigin/security_origin.h"
-#include "third_party/blink/renderer/platform/weborigin/security_origin_hash.h"
 #include "third_party/blink/renderer/platform/wtf/assertions.h"
 #include "third_party/blink/renderer/platform/wtf/functional.h"
 #include "third_party/blink/renderer/platform/wtf/std_lib_extras.h"

third_party/blink/renderer/platform/loader/fetch/memory_cache.cc

@@ -27,7 +27,6 @@
 #include "third_party/blink/renderer/platform/instrumentation/tracing/trace_event.h"
 #include "third_party/blink/renderer/platform/loader/fetch/resource_loading_log.h"
 #include "third_party/blink/renderer/platform/weborigin/security_origin.h"
-#include "third_party/blink/renderer/platform/weborigin/security_origin_hash.h"
 #include "third_party/blink/renderer/platform/wtf/assertions.h"
 #include "third_party/blink/renderer/platform/wtf/math_extras.h"
 #include "third_party/blink/renderer/platform/wtf/text/cstring.h"

third_party/blink/renderer/platform/weborigin/security_origin_hash.h

@@ -36,6 +36,10 @@
 
 namespace blink {
 
+// This Hash implements the "same origin" equality relation between two origins.
+// As such it ignores the domain that might or might not be set on the origin.
+// If you need "same origin-domain" equality you'll need to use a different hash
+// function.
 struct SecurityOriginHash {
   STATIC_ONLY(SecurityOriginHash);
   static unsigned GetHash(const SecurityOrigin* origin) {
@@ -53,19 +57,7 @@ struct SecurityOriginHash {
     if (!a || !b)
       return a == b;
 
-    if (a == b)
-      return true;
-
-    if (!a->IsSameSchemeHostPort(b))
-      return false;
-
-    if (a->DomainWasSetInDOM() != b->DomainWasSetInDOM())
-      return false;
-
-    if (a->DomainWasSetInDOM() && a->Domain() != b->Domain())
-      return false;
-
-    return true;
+    return a->IsSameSchemeHostPort(b);
   }
   static bool Equal(const SecurityOrigin* a,
                     const scoped_refptr<const SecurityOrigin>& b) {
@@ -85,13 +77,4 @@ struct SecurityOriginHash {
 
 }  // namespace blink
 
-namespace WTF {
-
-template <>
-struct DefaultHash<scoped_refptr<const blink::SecurityOrigin>> {
-  typedef blink::SecurityOriginHash Hash;
-};
-
-}  // namespace WTF
-
 #endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_WEBORIGIN_SECURITY_ORIGIN_HASH_H_