Nits to webrtc_event_log_manager.cc/h

Bug: None
Change-Id: I8bed811ba52e7ecf0dd772c0222bc57d8b99f46d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1886821Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Commit-Queue: Elad Alon <eladalon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710729}

chrome/browser/media/webrtc/webrtc_event_log_manager.cc

@@ -4,6 +4,8 @@
 
 #include "chrome/browser/media/webrtc/webrtc_event_log_manager.h"
 
+#include <limits>
+
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/task/post_task.h"
@@ -186,6 +188,7 @@ WebRtcEventLogManager::WebRtcEventLogManager()
            base::TaskPriority::BEST_EFFORT,
            base::ThreadPolicy::PREFER_BACKGROUND,
            base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN})),
+      num_user_blocking_tasks_(0),
       remote_logging_feature_enabled_(IsRemoteLoggingFeatureEnabled()),
       local_logs_observer_(nullptr),
       remote_logs_observer_(nullptr),
@@ -482,10 +485,10 @@ void WebRtcEventLogManager::ClearCacheForBrowserContext(
   const auto browser_context_id = GetBrowserContextId(browser_context);
   DCHECK_NE(browser_context_id, kNullBrowserContextId);
 
-  // |task_runner_| is USER_BLOCKING when there are pending tasks to clear the
-  // cache.
-  ++num_pending_clear_cache_;
-  task_runner_->UpdatePriority(base::TaskPriority::USER_BLOCKING);
+  DCHECK_LT(num_user_blocking_tasks_, std::numeric_limits<size_t>::max());
+  if (++num_user_blocking_tasks_ == 1) {
+    task_runner_->UpdatePriority(base::TaskPriority::USER_BLOCKING);
+  }
 
   // |this| is destroyed by ~BrowserProcessImpl(), so base::Unretained(this)
   // will not be dereferenced after destruction.
@@ -951,12 +954,10 @@ void WebRtcEventLogManager::ClearCacheForBrowserContextInternal(
 void WebRtcEventLogManager::OnClearCacheForBrowserContextDoneInternal(
     base::OnceClosure reply) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  DCHECK_GT(num_pending_clear_cache_, 0);
-  // |task_runner_| is BEST_EFFORT when there are no pending tasks to clear the
-  // cache.
-  --num_pending_clear_cache_;
-  if (num_pending_clear_cache_ == 0)
+  DCHECK_GT(num_user_blocking_tasks_, 0u);
+  if (--num_user_blocking_tasks_ == 0) {
     task_runner_->UpdatePriority(base::TaskPriority::BEST_EFFORT);
+  }
   std::move(reply).Run();
 }
 

chrome/browser/media/webrtc/webrtc_event_log_manager.h

@@ -368,9 +368,11 @@ class WebRtcEventLogManager final : public content::RenderProcessHostObserver,
   // tasks are allowed.
   scoped_refptr<base::UpdateableSequencedTaskRunner> task_runner_;
 
-  // The number of pending tasks to clear the cache. The priority of
-  // |task_runner_| is increased to USER_BLOCKING when this is non-zero.
-  int num_pending_clear_cache_ = 0;
+  // The number of user-blocking tasks.
+  // The priority of |task_runner_| is increased to USER_BLOCKING when this is
+  // non-zero, and reduced to BEST_EFFORT when zero.
+  // This object is only to be accessed on the UI thread.
+  size_t num_user_blocking_tasks_;
 
   // Indicates whether remote-bound logging is generally allowed, although
   // possibly not for all profiles. This makes it possible for remote-bound to