|request_initiator_site_lock| enforcement - attempt #2.

This CL starts treating |request_initiator| that doesn't match
|request_initiator_site_lock| as a bad IPC message and ignoring such
malformed resource requests.

NetworkService.URLLoader.RequestInitiatorOriginLockCompatibility UMA is
non-zero in recent Canary releases.  Therefore it is possible
that this CL will get reverted after gathering sufficient number of
DumpWithoutCrashing reports to understand why the lock doesn't match the
initiator in some real world scenarios.

Bug: 920634
Change-Id: If4fbdb6336703f53784c036ca5d9e408ff223d78
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2006113
Auto-Submit: Łukasz Anforowicz <lukasza@chromium.org>
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#739359}

services/network/cors/cors_url_loader_factory.cc

@@ -308,7 +308,12 @@ bool CorsURLLoaderFactory::IsSane(const NetworkContext* context,
       // TODO(lukasza): https://crbug.com/920634: Report bad message and return
       // false below.
       NOTREACHED();
-      break;
+      debug::ScopedOriginCrashKey initiator_lock_crash_key(
+          debug::GetRequestInitiatorSiteLockCrashKey(),
+          request_initiator_site_lock_);
+      mojo::ReportBadMessage(
+          "CorsURLLoaderFactory: lock VS initiator mismatch");
+      return false;
   }
 
   if (context) {

services/network/crash_keys.cc

@@ -26,6 +26,12 @@ base::debug::CrashKeyString* GetRequestInitiatorCrashKey() {
 
 }  // namespace
 
+base::debug::CrashKeyString* GetRequestInitiatorSiteLockCrashKey() {
+  static auto* crash_key = base::debug::AllocateCrashKeyString(
+      "request_initiator_site_lock", base::debug::CrashKeySize::Size64);
+  return crash_key;
+}
+
 ScopedOriginCrashKey::ScopedOriginCrashKey(
     base::debug::CrashKeyString* crash_key,
     const base::Optional<url::Origin>& value)

services/network/crash_keys.h

@@ -15,6 +15,8 @@ struct ResourceRequest;
 
 namespace debug {
 
+base::debug::CrashKeyString* GetRequestInitiatorSiteLockCrashKey();
+
 class ScopedOriginCrashKey : public base::debug::ScopedCrashKeyString {
  public:
   ScopedOriginCrashKey(base::debug::CrashKeyString* crash_key,