cc: Add TaskGraphRunner sub-namespaces with task concurrency limits.

cc/resources/tile_task_worker_pool.cc

 // Copyright 2013 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 "cc/resources/tile_task_worker_pool.h"
 
 #include <algorithm>
 
 #include "base/lazy_instance.h"
 #include "base/strings/stringprintf.h"
@@ skipping 145 matching lines @@
       task->ScheduleOnOriginThread(client);
       task->DidSchedule();
     }
   }
 }
 
 // static
 void TileTaskWorkerPool::InsertNodeForTask(TaskGraph* graph,
                                            TileTask* task,
                                            unsigned priority,
-                                           size_t dependencies) {
+                                           size_t dependencies,
+                                           int sub_namespace,
+                                           int max_concurrent_tasks) {
   DCHECK(std::find_if(graph->nodes.begin(), graph->nodes.end(),
                       TaskGraph::Node::TaskComparator(task)) ==
          graph->nodes.end());
-  graph->nodes.push_back(TaskGraph::Node(task, priority, dependencies));
+  graph->nodes.push_back(TaskGraph::Node(task, priority, dependencies,
+                                         sub_namespace, max_concurrent_tasks));
 }
 
 // static
 void TileTaskWorkerPool::InsertNodesForRasterTask(
     TaskGraph* graph,
     RasterTask* raster_task,
     const ImageDecodeTask::Vector& decode_tasks,
-    unsigned priority) {
+    unsigned priority,
+    int sub_namespace,
+    int max_concurrent_tasks) {
   size_t dependencies = 0u;
 
   // Insert image decode tasks.
   for (ImageDecodeTask::Vector::const_iterator it = decode_tasks.begin();
        it != decode_tasks.end(); ++it) {
     ImageDecodeTask* decode_task = it->get();
 
     // Skip if already decoded.
     if (decode_task->HasCompleted())
       continue;
 
     dependencies++;
 
     // Add decode task if it doesn't already exists in graph.
     TaskGraph::Node::Vector::iterator decode_it =
         std::find_if(graph->nodes.begin(), graph->nodes.end(),
                      TaskGraph::Node::TaskComparator(decode_task));
     if (decode_it == graph->nodes.end())
-      InsertNodeForTask(graph, decode_task, priority, 0u);
+      InsertNodeForTask(graph, decode_task, priority, 0u, kDefaultSubNamespace,

[danakj, 2015/02/23 18:45:01]

when using the defaults can you leave a comment why?

+                        kDefaultMaxConcurrentTasks);
 
     graph->edges.push_back(TaskGraph::Edge(decode_task, raster_task));
   }
 
-  InsertNodeForTask(graph, raster_task, priority, dependencies);
+  InsertNodeForTask(graph, raster_task, priority, dependencies, sub_namespace,
+                    max_concurrent_tasks);
 }
 
 static bool IsSupportedPlaybackToMemoryFormat(ResourceFormat format) {
   switch (format) {
     case RGBA_4444:
     case RGBA_8888:
     case BGRA_8888:
       return true;
     case ALPHA_8:
     case LUMINANCE_8:
@@ skipping 50 matching lines @@
   // TODO(kaanb): The GL pipeline assumes a 4-byte alignment for the
   // bitmap data. There will be no need to call SkAlign4 once crbug.com/293728
   // is fixed.
   const size_t dst_row_bytes = SkAlign4(dst_info.minRowBytes());
   DCHECK_EQ(0u, dst_row_bytes % 4);
   bool success = canvas->readPixels(dst_info, memory, dst_row_bytes, 0, 0);
   DCHECK_EQ(true, success);
 }
 
 }  // namespace cc