Use constexpr TaskTraits constructor in chrome.

chrome/browser/android/thumbnail/thumbnail_cache.cc

 // Copyright 2014 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 "chrome/browser/android/thumbnail/thumbnail_cache.h"
 
 #include <algorithm>
 #include <cmath>
 #include <utility>
 
@@ skipping 369 matching lines @@
       post_compression_task = base::Bind(&ThumbnailCache::PostCompressionTask,
                                          weak_factory_.GetWeakPtr(),
                                          tab_id,
                                          time_stamp,
                                          scale);
 
   gfx::Size raw_data_size(bitmap.width(), bitmap.height());
   gfx::Size encoded_size = GetEncodedSize(
       raw_data_size, ui_resource_provider_->SupportsETC1NonPowerOfTwo());
 
-  base::PostTaskWithTraits(
-      FROM_HERE, base::TaskTraits()
-                     .WithPriority(base::TaskPriority::BACKGROUND)
-                     .WithShutdownBehavior(
-                         base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN),
-      base::Bind(&ThumbnailCache::CompressionTask, bitmap, encoded_size,
-                 post_compression_task));
+  base::PostTaskWithTraits(FROM_HERE,
+                           {base::TaskPriority::BACKGROUND,
+                            base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN},
+                           base::Bind(&ThumbnailCache::CompressionTask, bitmap,
+                                      encoded_size, post_compression_task));
 }
 
 void ThumbnailCache::ReadNextThumbnail() {
   if (read_queue_.empty() || read_in_progress_)
     return;
 
   TabId tab_id = read_queue_.front();
   read_in_progress_ = true;
 
   base::Callback<void(sk_sp<SkPixelRef>, float, const gfx::Size&)>
@@ skipping 360 matching lines @@
     if (!valid_contents) {
       content_size.SetSize(0, 0);
             scale = 0.f;
             compressed_data.reset();
             base::DeleteFile(file_path, false);
     }
   }
 
   if (decompress) {
     base::PostTaskWithTraits(
-        FROM_HERE,
-        base::TaskTraits().WithPriority(base::TaskPriority::BACKGROUND),
+        FROM_HERE, {base::TaskPriority::BACKGROUND},
         base::Bind(post_read_task, std::move(compressed_data), scale,
                    content_size));
   } else {
     content::BrowserThread::PostTask(
         content::BrowserThread::UI,
         FROM_HERE,
         base::Bind(post_read_task, std::move(compressed_data), scale,
                    content_size));
   }
 }
@@ skipping 135 matching lines @@
   return std::make_pair(dst_bitmap, new_scale * scale);
 }
 
 void ThumbnailCache::OnMemoryPressure(
     base::MemoryPressureListener::MemoryPressureLevel level) {
   if (level == base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL) {
     cache_.Clear();
     approximation_cache_.Clear();
   }
 }