Add more debugging info to find the source of invalid appcache handles.

This is a follow-up to http://crrev.com/c/2216913. We are still
seeing invalid handles after that change so this CL adds some more
debugging info the help figure out what call stacks are creating
these invalid handles. I've also added a scoped crash key to
capture some RenderFrameHostImpl state since that seems like the most
likely caller to be triggering this problem.

Bug: 977169, 1086306
Change-Id: I023c159f4e1d2cd9a3fb018a7867dbdb42c2b0f7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2220893
Auto-Submit: Aaron Colwell <acolwell@chromium.org>
Commit-Queue: Marijn Kruisselbrink <mek@chromium.org>
Reviewed-by: Marijn Kruisselbrink <mek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#773220}

content/browser/appcache/appcache_backend_impl.cc

@@ -9,6 +9,7 @@
 #include <utility>
 #include <vector>
 
+#include "base/debug/dump_without_crashing.h"
 #include "content/browser/appcache/appcache.h"
 #include "content/browser/appcache/appcache_group.h"
 #include "content/browser/appcache/appcache_service_impl.h"
@@ -27,6 +28,10 @@ AppCacheBackendImpl::AppCacheBackendImpl(AppCacheServiceImpl* service,
           ChildProcessSecurityPolicyImpl::GetInstance()->CreateHandle(
               process_id)) {
   DCHECK(service);
+  DCHECK(security_policy_handle_.is_valid());
+
+  if (!security_policy_handle_.is_valid())
+    base::debug::DumpWithoutCrashing();
 }
 
 AppCacheBackendImpl::~AppCacheBackendImpl() = default;

content/browser/frame_host/render_frame_host_impl.cc

@@ -14,6 +14,7 @@
 #include "base/command_line.h"
 #include "base/containers/queue.h"
 #include "base/debug/alias.h"
+#include "base/debug/crash_logging.h"
 #include "base/debug/dump_without_crashing.h"
 #include "base/hash/hash.h"
 #include "base/i18n/character_encoding.h"
@@ -7384,6 +7385,15 @@ void RenderFrameHostImpl::GetInterface(
 void RenderFrameHostImpl::CreateAppCacheBackend(
     mojo::PendingReceiver<blink::mojom::AppCacheBackend> receiver) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  static auto* crash_key = base::debug::AllocateCrashKeyString(
+      "CreateAppCacheBackend-data", base::debug::CrashKeySize::Size64);
+  std::string data = base::StringPrintf(
+      "f=%d br=%d irfl=%d iiand=%d fid=%d", frame_.is_bound(),
+      broker_receiver_.is_bound(), IsRenderFrameLive(),
+      GetProcess()->IsInitializedAndNotDead(),
+      RenderProcessHost::FromID(GetProcess()->GetID()) != nullptr);
+  base::debug::ScopedCrashKeyString scoped_crash_key(crash_key, data);
+
   auto* storage_partition_impl =
       static_cast<StoragePartitionImpl*>(GetProcess()->GetStoragePartition());
   storage_partition_impl->GetAppCacheService()->CreateBackend(