cc: Add image decode queue functionality to image manager.

cc/raster/task.cc

Index: cc/raster/task.cc
diff --git a/cc/raster/task.cc b/cc/raster/task.cc
index 94e413f46d8cbf6df6d1631aaca7e3ab51d9a381..94486fd523a41812647ec939fcf0c0d6e27c7f78 100644
--- a/cc/raster/task.cc
+++ b/cc/raster/task.cc
@@ -18,6 +18,10 @@ TaskState::~TaskState() {
          "CANCELED state.";
 }
 
+bool TaskState::IsNew() const {
+  return value_ == Value::NEW;
+}
+
 bool TaskState::IsScheduled() const {
   return value_ == Value::SCHEDULED;
 }
@@ -38,6 +42,23 @@ void TaskState::Reset() {
   value_ = Value::NEW;
 }
 
+std::string TaskState::ToString() const {
+  switch (value_) {
+    case Value::NEW:
+      return "NEW";
+    case Value::SCHEDULED:
+      return "SCHEDULED";
+    case Value::RUNNING:
+      return "RUNNING";
+    case Value::FINISHED:
+      return "FINISHED";
+    case Value::CANCELED:
+      return "CANCELED";
+  }
+  NOTREACHED();
+  return "";
+}
+
 void TaskState::DidSchedule() {
   DCHECK(value_ == Value::NEW)
       << "Task should be in NEW state to get scheduled.";