Forcibly clear worker ref counts on shutdown.

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 126df71c74b3b788f1836af075d0ad7733688228..54d19daa76cdb43f7d018033b5827c3866899e06 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -675,6 +675,7 @@ RenderProcessHostImpl::RenderProcessHostImpl(
       child_token_(mojo::edk::GenerateRandomToken()),
       service_worker_ref_count_(0),
       shared_worker_ref_count_(0),
+      is_worker_ref_count_disabled_(false),
       visible_widgets_(0),
       is_process_backgrounded_(false),
       is_initialized_(false),
@@ -1341,6 +1342,7 @@ bool RenderProcessHostImpl::IsProcessBackgrounded() const {
 
 void RenderProcessHostImpl::IncrementServiceWorkerRefCount() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(!is_worker_ref_count_disabled_);
   ++service_worker_ref_count_;
   if (worker_ref_count() > max_worker_count_)
     max_worker_count_ = worker_ref_count();
@@ -1348,7 +1350,8 @@ void RenderProcessHostImpl::IncrementServiceWorkerRefCount() {
 
 void RenderProcessHostImpl::DecrementServiceWorkerRefCount() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  DCHECK_GT(worker_ref_count(), 0UL);
+  DCHECK(!is_worker_ref_count_disabled_);
+  DCHECK_GT(worker_ref_count(), 0U);
   --service_worker_ref_count_;
   if (worker_ref_count() == 0)
     Cleanup();
@@ -1356,6 +1359,7 @@ void RenderProcessHostImpl::DecrementServiceWorkerRefCount() {
 
 void RenderProcessHostImpl::IncrementSharedWorkerRefCount() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(!is_worker_ref_count_disabled_);
   ++shared_worker_ref_count_;
   if (worker_ref_count() > max_worker_count_)
     max_worker_count_ = worker_ref_count();
@@ -1363,12 +1367,28 @@ void RenderProcessHostImpl::IncrementSharedWorkerRefCount() {
 
 void RenderProcessHostImpl::DecrementSharedWorkerRefCount() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  DCHECK_GT(worker_ref_count(), 0UL);
+  DCHECK(!is_worker_ref_count_disabled_);
+  DCHECK_GT(worker_ref_count(), 0U);
   --shared_worker_ref_count_;
   if (worker_ref_count() == 0)
     Cleanup();
 }
 
+void RenderProcessHostImpl::ForceReleaseWorkerRefCounts() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  is_worker_ref_count_disabled_ = true;

[jam, 2016/09/14 17:10:49]

DCHECK(!is_worker_ref_count_disabled_); before this?

[falken, 2016/09/21 08:59:43]

Done.

+  if (!worker_ref_count())
+    return;
+  service_worker_ref_count_ = 0;
+  shared_worker_ref_count_ = 0;
+  Cleanup();
+}
+
+bool RenderProcessHostImpl::IsWorkerRefCountDisabled() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  return is_worker_ref_count_disabled_;
+}
+
 void RenderProcessHostImpl::PurgeAndSuspend() {
   Send(new ChildProcessMsg_PurgeAndSuspend());
 }