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

cc/resources/task_graph_runner_unittest.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 "cc/resources/task_graph_runner.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/synchronization/lock.h"
@@ skipping 64 matching lines @@
 
   const std::vector<unsigned>& on_task_completed_ids(int namespace_index) {
     return on_task_completed_ids_[namespace_index];
   }
 
   void ScheduleTasks(int namespace_index, const std::vector<TaskInfo>& tasks) {
     Task::Vector new_tasks;
     Task::Vector new_dependents;
     TaskGraph new_graph;
 
+    int sub_namespace = 0;
+    int max_concurrent_tasks = 4;

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

no tests with different values to verify this works? 

+
     for (std::vector<TaskInfo>::const_iterator it = tasks.begin();
          it != tasks.end();
          ++it) {
       scoped_refptr<FakeTaskImpl> new_task(
           new FakeTaskImpl(this, it->namespace_index, it->id));
-      new_graph.nodes.push_back(
-          TaskGraph::Node(new_task.get(), it->priority, 0u));
+      new_graph.nodes.push_back(TaskGraph::Node(new_task.get(), it->priority,
+                                                0u, sub_namespace,
+                                                max_concurrent_tasks));
       for (unsigned i = 0; i < it->dependent_count; ++i) {
         scoped_refptr<FakeDependentTaskImpl> new_dependent_task(
             new FakeDependentTaskImpl(
                 this, it->namespace_index, it->dependent_id));
         new_graph.nodes.push_back(
-            TaskGraph::Node(new_dependent_task.get(), it->priority, 1u));
+            TaskGraph::Node(new_dependent_task.get(), it->priority, 1u,
+                            sub_namespace, max_concurrent_tasks));
         new_graph.edges.push_back(
             TaskGraph::Edge(new_task.get(), new_dependent_task.get()));
 
         new_dependents.push_back(new_dependent_task.get());
       }
 
       new_tasks.push_back(new_task.get());
     }
 
     task_graph_runner_->ScheduleTasks(namespace_token_[namespace_index],
@@ skipping 214 matching lines @@
     EXPECT_EQ(0u, run_task_ids(i)[2]);
     EXPECT_EQ(2u, run_task_ids(i)[3]);
     ASSERT_EQ(2u, on_task_completed_ids(i).size());
     EXPECT_EQ(1u, on_task_completed_ids(i)[0]);
     EXPECT_EQ(0u, on_task_completed_ids(i)[1]);
   }
 }
 
 }  // namespace
 }  // namespace cc