font-service: Track one more pending WaitableEvent.

components/font_service/public/cpp/font_service_thread.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/font_service/public/cpp/font_service_thread.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/files/file.h"
@@ skipping 86 matching lines @@
     *out_valid = false;
     done_event->Signal();
     return;
   }
 
   TypefaceStylePtr style(TypefaceStyle::New());
   style->weight = requested_style.weight();
   style->width = requested_style.width();
   style->slant = static_cast<TypefaceSlant>(requested_style.slant());
 
+  pending_waitable_events_.insert(done_event);
   font_service_->MatchFamilyName(
       mojo::String(family_name), std::move(style),
       base::Bind(&FontServiceThread::OnMatchFamilyNameComplete, this,
                  done_event, out_valid, out_font_identity, out_family_name,
                  out_style));
 }
 
 void FontServiceThread::OnMatchFamilyNameComplete(
     base::WaitableEvent* done_event,
     bool* out_valid,
     SkFontConfigInterface::FontIdentity* out_font_identity,
     SkString* out_family_name,
     SkFontStyle* out_style,
     FontIdentityPtr font_identity,
     mojo::String family_name,
     TypefaceStylePtr style) {
   DCHECK_EQ(GetThreadId(), base::PlatformThread::CurrentId());
+  pending_waitable_events_.erase(done_event);
 
   *out_valid = font_identity;
   if (font_identity) {
     out_font_identity->fID = font_identity->id;
     out_font_identity->fTTCIndex = font_identity->ttc_index;
     out_font_identity->fString = font_identity->str_representation.data();
     // TODO(erg): fStyle isn't set. This is rather odd, however it matches the
     // behaviour of the current Linux IPC version.
 
     *out_family_name = family_name.data();
@@ skipping 47 matching lines @@
       base::Bind(&FontServiceThread::OnFontServiceConnectionError,
                  weak_factory_.GetWeakPtr()));
 }
 
 void FontServiceThread::CleanUp() {
   font_service_.reset();
 }
 
 }  // namespace internal
 }  // namespace font_service