cc: Don't infinitely throttle large raster tasks

cc/resources/pixel_buffer_raster_worker_pool.cc

Index: cc/resources/pixel_buffer_raster_worker_pool.cc
diff --git a/cc/resources/pixel_buffer_raster_worker_pool.cc b/cc/resources/pixel_buffer_raster_worker_pool.cc
index d7554736942a66ee541c065c99320385c42d0234..f980195fb3bc318d5c6de7df8f6465cf2dcd2230 100644
--- a/cc/resources/pixel_buffer_raster_worker_pool.cc
+++ b/cc/resources/pixel_buffer_raster_worker_pool.cc
@@ -515,10 +515,13 @@ void PixelBufferRasterWorkerPool::ScheduleMoreTasks() {
       continue;
     }
 
-    // All raster tasks need to be throttled by bytes of pending uploads.
+    // All raster tasks need to be throttled by bytes of pending uploads,
+    // but if it's the first task allow it to complete no matter what its size,

[reveman, 2014/08/21 01:15:47]

nit: maybe "only" instead of "first" as this is effected by previously scheduled
tasks and not only the tasks being scheduled at this time

[enne (OOO), 2014/08/21 01:34:15]

Done.

+    // to prevent starvation of the task queue.
     size_t new_bytes_pending_upload = bytes_pending_upload;
     new_bytes_pending_upload += task->resource()->bytes();
-    if (new_bytes_pending_upload > max_bytes_pending_upload_) {
+    if (new_bytes_pending_upload > max_bytes_pending_upload_ &&
+        bytes_pending_upload > 0) {

[reveman, 2014/08/21 01:15:47]

nit: s/bytes_pending_upload > 0/bytes_pending_upload/

[enne (OOO), 2014/08/21 01:34:15]

Done.

       did_throttle_raster_tasks = true;
       if (item.required_for_activation)
         did_throttle_raster_tasks_required_for_activation = true;