Remove outdated comment for CanAccessSessionStorage.

https://github.com/whatwg/html/issues/3283 was resolved to change the spec to not
allow access to session storage in opaque origins, matching our implementation.

Bug: 677733
Change-Id: I23da98f166f0845312a0c8ec386d84ac2e3c74f3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2579023
Commit-Queue: Marijn Kruisselbrink <mek@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Auto-Submit: Marijn Kruisselbrink <mek@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#834818}

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

@@ -233,10 +233,6 @@ class PLATFORM_EXPORT SecurityOrigin : public RefCounted<SecurityOrigin> {
   bool CanAccessNativeFileSystem() const { return !IsOpaque(); }
   bool CanAccessCacheStorage() const { return !IsOpaque(); }
   bool CanAccessLocks() const { return !IsOpaque(); }
-
-  // Technically, we should always allow access to sessionStorage, but we
-  // currently don't handle creating a sessionStorage area for opaque
-  // origins.
   bool CanAccessSessionStorage() const { return !IsOpaque(); }
 
   // The local SecurityOrigin is the most privileged SecurityOrigin.