Removing instrumentation for bug 1153966/1153961

The culprit has been reverted:
https://chromium-review.googlesource.com/c/chromium/src/+/2625867
and we verified the crashed were gone.

R=danakj@chromium.org

Bug: 1153966,1153961
Change-Id: Ic99bbed56808188c92a34b8761e43b5621cf9e0b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2632988Reviewed-by: danakj <danakj@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
Auto-Submit: Arthur Sonzogni <arthursonzogni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844154}

content/browser/renderer_host/render_widget_host_impl.cc

@@ -1772,12 +1772,10 @@ void RenderWidgetHostImpl::RemoveInputEventObserver(
 
 void RenderWidgetHostImpl::AddObserver(RenderWidgetHostObserver* observer) {
   observers_.AddObserver(observer);
-  observers_size_for_debug_++;
 }
 
 void RenderWidgetHostImpl::RemoveObserver(RenderWidgetHostObserver* observer) {
   observers_.RemoveObserver(observer);
-  observers_size_for_debug_--;
 }
 
 void RenderWidgetHostImpl::GetScreenInfo(blink::ScreenInfo* result) {
@@ -2230,28 +2228,11 @@ void RenderWidgetHostImpl::SetAutoResize(bool enable,
 }
 
 void RenderWidgetHostImpl::Destroy(bool also_delete) {
-  // TODO(https://crbug.com/1153966): Turns this back into a DCHECK once the bug
-  // is fixed.
-  CHECK(!destroyed_);
+  DCHECK(!destroyed_);
   destroyed_ = true;
 
-  // TODO(https://crbug.com/1153966): This is instrumentation about a bug
-  // happening while iterating on the |observers_|. Remove this when the bug
-  // will be fixed.
-  base::WeakPtr<RenderWidgetHostImpl> weak_ptr = GetWeakPtr();
-  int observer_list_iteration_before_call = 0;
-  int observer_list_iteration_after_call = 0;
-  int observer_list_size = observers_size_for_debug_;
-  base::debug::Alias(&observer_list_iteration_before_call);
-  base::debug::Alias(&observer_list_iteration_after_call);
-  base::debug::Alias(&observer_list_size);
-
-  for (auto& observer : observers_) {
-    observer_list_iteration_before_call++;
+  for (auto& observer : observers_)
     observer.RenderWidgetHostDestroyed(this);
-    observer_list_iteration_after_call++;
-    CHECK(weak_ptr);
-  }
 
   NotificationService::current()->Notify(
       NOTIFICATION_RENDER_WIDGET_HOST_DESTROYED, Source<RenderWidgetHost>(this),

content/browser/renderer_host/render_widget_host_impl.h

@@ -1226,9 +1226,6 @@ class CONTENT_EXPORT RenderWidgetHostImpl
   // The observers watching us.
   base::ObserverList<RenderWidgetHostObserver> observers_;
 
-  // TODO(https://crbug.com/1153966): Remove this after closing this bug.
-  int observers_size_for_debug_ = 0;
-
   // This is true if the renderer is currently unresponsive.
   bool is_unresponsive_ = false;
 

content/public/browser/render_process_host_observer.cc

@@ -8,9 +8,7 @@
 namespace content {
 
 RenderProcessHostObserver::~RenderProcessHostObserver() {
-  // TODO(https://crbug.com/1153961): Instrumentation. When fixed, decide if
-  // this CHECK should be removed or turned into a DCHECK.
-  CHECK(!IsInObserverList());
+  DCHECK(!IsInObserverList());
 }
 
 }  // namespace content

content/public/browser/render_widget_host_observer.cc

@@ -8,9 +8,7 @@
 namespace content {
 
 RenderWidgetHostObserver::~RenderWidgetHostObserver() {
-  // TODO(https://crbug.com/1153966): Instrumentation. When fixed, decide if
-  // this CHECK should be removed or turned into a DCHECK.
-  CHECK(!IsInObserverList());
+  DCHECK(!IsInObserverList());
 }
 
 }  // namespace content