cc: Simplify task and its derived classes.

cc/test/task_graph_runner_test_template.h

Index: cc/test/task_graph_runner_test_template.h
diff --git a/cc/test/task_graph_runner_test_template.h b/cc/test/task_graph_runner_test_template.h
index d4175433a02e2a9076028361deea60ab6c7548af..9336088e9c02aca9ff3aad9eb8e5ee686411afe0 100644
--- a/cc/test/task_graph_runner_test_template.h
+++ b/cc/test/task_graph_runner_test_template.h
@@ -55,15 +55,15 @@ class TaskGraphRunnerTestBase {
   static const int kNamespaceCount = 3;
 
  protected:
-  class FakeTaskImpl : public Task {
+  class FakeTaskImpl : public DependencyTask {
    public:
     FakeTaskImpl(TaskGraphRunnerTestBase* test, int namespace_index, int id)
         : test_(test), namespace_index_(namespace_index), id_(id) {}
 
     // Overridden from Task:
     void RunOnWorkerThread() override;
-
-    virtual void CompleteOnOriginThread();
+    void ScheduleOnOriginThread(DependencyTaskClient* client) override{};
+    void CompleteOnOriginThread(DependencyTaskClient* client) override;
 
    protected:
     ~FakeTaskImpl() override {}
@@ -84,7 +84,7 @@ class TaskGraphRunnerTestBase {
         : FakeTaskImpl(test, namespace_index, id) {}
 
     // Overridden from FakeTaskImpl:
-    void CompleteOnOriginThread() override {}
+    void CompleteOnOriginThread(DependencyTaskClient* client) override {}
 
    private:
     ~FakeDependentTaskImpl() override {}
@@ -94,8 +94,8 @@ class TaskGraphRunnerTestBase {
 
   TaskGraphRunner* task_graph_runner_;
   NamespaceToken namespace_token_[kNamespaceCount];
-  Task::Vector tasks_[kNamespaceCount];
-  Task::Vector dependents_[kNamespaceCount];
+  DependencyTask::Vector tasks_[kNamespaceCount];
+  DependencyTask::Vector dependents_[kNamespaceCount];
   std::vector<unsigned> run_task_ids_[kNamespaceCount];
   base::Lock run_task_ids_lock_;
   std::vector<unsigned> on_task_completed_ids_[kNamespaceCount];