cc: Replace RasterTaskStateMap with a vector and brute force search instead of hash map lookups.

cc/resources/pixel_buffer_raster_worker_pool.h

Index: cc/resources/pixel_buffer_raster_worker_pool.h
diff --git a/cc/resources/pixel_buffer_raster_worker_pool.h b/cc/resources/pixel_buffer_raster_worker_pool.h
index fe34d1b0268faa8c16d5604be88933e25ec5170e..134c16191ccaa48e0c6a7c4cd23763121b92821a 100644
--- a/cc/resources/pixel_buffer_raster_worker_pool.h
+++ b/cc/resources/pixel_buffer_raster_worker_pool.h
@@ -5,22 +5,10 @@
 #ifndef CC_RESOURCES_PIXEL_BUFFER_RASTER_WORKER_POOL_H_
 #define CC_RESOURCES_PIXEL_BUFFER_RASTER_WORKER_POOL_H_
 
-#include <deque>
+#include <vector>
 
-#include "base/containers/hash_tables.h"
 #include "cc/resources/raster_worker_pool.h"
 
-#if defined(COMPILER_GCC)
-namespace BASE_HASH_NAMESPACE {
-template <>
-struct hash<cc::internal::WorkerPoolTask*> {
-  size_t operator()(cc::internal::WorkerPoolTask* ptr) const {
-    return hash<size_t>()(reinterpret_cast<size_t>(ptr));
-  }
-};
-}  // namespace BASE_HASH_NAMESPACE
-#endif  // COMPILER
-
 namespace cc {
 
 class CC_EXPORT PixelBufferRasterWorkerPool : public RasterWorkerPool {
@@ -51,8 +39,27 @@ class CC_EXPORT PixelBufferRasterWorkerPool : public RasterWorkerPool {
 
  private:
   struct RasterTaskState {
-    RasterTaskState()
-        : type(UNSCHEDULED), resource(NULL), required_for_activation(false) {}
+    class TaskComparator {

[vmpstr, 2014/02/21 18:39:41]

I know this is consistent with other classes in task graph runner / worker pool
system, but is there a better name for this class? TaskComparator to me means
something that compares two arbitrary tasks to determine which one is "better"
or something..

This is more like a TaskFinder where it only returns true if the passed argument
matches the constructor argument. I don't know, this is mostly a big nit but
feel free to leave it as is, since I don't have any good suggestions.

[reveman, 2014/02/22 11:32:01]

Maybe IsTask or IsTaskComparator would be better as the result is code such as:

find_if(states.begin(), states.end(), IsTask(task))

I would have to change this everywhere though so better as a follow up. 

[vmpstr, 2014/02/24 17:37:58]

IsTask or IsTaskComparator or IsTaskClosure or something all sound good to me.
As a follow up sounds good as well.

+     public:
+      explicit TaskComparator(const internal::WorkerPoolTask* task)
+          : task_(task) {}
+
+      bool operator()(const RasterTaskState& state) const {
+        return state.task == task_;
+      }
+
+     private:
+      const internal::WorkerPoolTask* task_;
+    };
+
+    typedef std::vector<RasterTaskState> Vector;
+
+    RasterTaskState(internal::WorkerPoolTask* task,
+                    bool required_for_activation)
+        : type(UNSCHEDULED),
+          task(task),
+          resource(NULL),
+          required_for_activation(required_for_activation) {}
 
     RasterTaskState& set_completed() {
       type = COMPLETED;
@@ -64,11 +71,10 @@ class CC_EXPORT PixelBufferRasterWorkerPool : public RasterWorkerPool {
     }
 
     enum { UNSCHEDULED, SCHEDULED, UPLOADING, COMPLETED } type;
+    internal::WorkerPoolTask* task;
     const Resource* resource;
     bool required_for_activation;
   };
-  typedef internal::WorkerPoolTask* RasterTaskMapKey;
-  typedef base::hash_map<RasterTaskMapKey, RasterTaskState> RasterTaskStateMap;
 
   // Overridden from RasterWorkerPool:
   virtual void OnRasterTasksFinished() OVERRIDE;
@@ -92,10 +98,11 @@ class CC_EXPORT PixelBufferRasterWorkerPool : public RasterWorkerPool {
   bool shutdown_;
 
   RasterTaskQueue raster_tasks_;
-  RasterTaskStateMap raster_task_states_;
+  RasterTaskState::Vector raster_task_states_;
+  RasterTaskState::Vector recycled_raster_task_states_;
   TaskDeque raster_tasks_with_pending_upload_;
-  TaskDeque completed_raster_tasks_;
-  TaskDeque completed_image_decode_tasks_;
+  TaskVector completed_raster_tasks_;
+  TaskVector completed_image_decode_tasks_;
 
   size_t scheduled_raster_task_count_;
   size_t raster_tasks_required_for_activation_count_;