SetNeedsRedraw directly when updating a visible tile.

cc/resources/tile_manager.cc

Index: cc/resources/tile_manager.cc
diff --git a/cc/resources/tile_manager.cc b/cc/resources/tile_manager.cc
index c785cf6fd7fec0b0b4c17985ef1be5f7540efaa0..654ffdfbf0417c3e889c4d04f6ed9e7f6d3d507b 100644
--- a/cc/resources/tile_manager.cc
+++ b/cc/resources/tile_manager.cc
@@ -239,9 +239,9 @@ TileManager::TileManager(
       scheduled_raster_task_limit_(scheduled_raster_task_limit),
       all_tiles_that_need_to_be_rasterized_are_scheduled_(true),
       rendering_stats_instrumentation_(rendering_stats_instrumentation),
-      did_initialize_visible_tile_(false),
       did_check_for_completed_tasks_since_last_schedule_tasks_(true),
       did_oom_on_last_assign_(false),
+      is_top_priority_uninitialized_tile_visible_and_active_(false),
       ready_to_activate_check_notifier_(
           task_runner_.get(),
           base::Bind(&TileManager::CheckIfReadyToActivate,
@@ -318,6 +318,10 @@ void TileManager::DidFinishRunningTasks(TaskSet task_set) {
   if (task_set == ALL) {
     TRACE_EVENT1("cc", "TileManager::DidFinishRunningTasks", "task_set", "ALL");
 
+    rasterizer_->CheckForCompletedTasks();
+    did_check_for_completed_tasks_since_last_schedule_tasks_ = true;
+    is_top_priority_uninitialized_tile_visible_and_active_ = false;

[reveman, 2014/10/31 00:44:01]

'false' might be incorrect. I guess we're assuming that ScheduleTasks will set
this to the correct value again below. That's a bit subtle.

+
     bool memory_usage_above_limit = resource_pool_->total_memory_usage_bytes() >
                                     global_state_.soft_memory_limit_in_bytes;
 
@@ -327,9 +331,6 @@ void TileManager::DidFinishRunningTasks(TaskSet task_set) {
         !memory_usage_above_limit)
       return;
 
-    rasterizer_->CheckForCompletedTasks();

[reveman, 2014/10/31 00:44:01]

This call has a cost. It's done here so it can be avoided when we early out
above. I don't think we should move it as that will likely have a performance
impact.

-    did_check_for_completed_tasks_since_last_schedule_tasks_ = true;
-
     TileVector tiles_that_need_to_be_rasterized;
     AssignGpuMemoryToTiles(&tiles_that_need_to_be_rasterized);
 
@@ -430,7 +431,7 @@ void TileManager::ManageTiles(const GlobalStateThatImpactsTilePriority& state) {
                         resource_pool_->acquired_memory_usage_bytes());
 }
 
-bool TileManager::UpdateVisibleTiles() {
+void TileManager::UpdateVisibleTiles() {
   TRACE_EVENT0("cc", "TileManager::UpdateVisibleTiles");
 
   rasterizer_->CheckForCompletedTasks();
@@ -443,10 +444,6 @@ bool TileManager::UpdateVisibleTiles() {
       "stats",
       RasterTaskCompletionStatsAsValue(update_visible_tiles_stats_));
   update_visible_tiles_stats_ = RasterTaskCompletionStats();
-
-  bool did_initialize_visible_tile = did_initialize_visible_tile_;
-  did_initialize_visible_tile_ = false;
-  return did_initialize_visible_tile;
 }
 
 scoped_refptr<base::debug::ConvertableToTraceFormat>
@@ -673,6 +670,14 @@ void TileManager::ScheduleTasks(
 
   raster_queue_.Reset();
 
+  if (tiles_that_need_to_be_rasterized.empty()) {
+    is_top_priority_uninitialized_tile_visible_and_active_ = false;
+  } else {
+    const Tile* tile = tiles_that_need_to_be_rasterized.front();
+    is_top_priority_uninitialized_tile_visible_and_active_ =
+        tile->is_active_and_visible_priority();

[reveman, 2014/10/31 00:44:01]

is_top_priority_uninitialized_tile_visible_and_active_ might be set to what we
want when is_top_priority_uninitialized_tile_visible_and_active() is currently
called but it looks like it would be incorrect after a call to
UpdateVisibleTiles().

+  }
+
   // Build a new task queue containing all task currently needed. Tasks
   // are added in order of priority, highest priority task first.
   for (TileVector::const_iterator it = tiles_that_need_to_be_rasterized.begin();
@@ -822,9 +827,6 @@ void TileManager::OnRasterTaskCompleted(
     mts.draw_info.resource_ = resource.Pass();
   }
 
-  if (tile->priority(ACTIVE_TREE).distance_to_visible == 0.f)
-    did_initialize_visible_tile_ = true;
-
   client_->NotifyTileStateChanged(tile);
 }