cc: Fix recursive call to TileManager::DispatchMoreTasks

Through a sequence of calls, DispatchMoreTasks can be called
recursively. Since it's not re-entrant it can cause undefined
behaviour, which caused crashes on ChromeOS and, I suspect,
on N7 when solid color prediction was turned on.

BUG=223722


Review URL: https://chromiumcodereview.appspot.com/12918027

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@191088 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 14 insertions, 2 deletions

diff --git a/cc/resources/tile_manager.cc b/cc/resources/tile_manager.cc
index c1e525d..b959bac 100644
--- a/cc/resources/tile_manager.cc
+++ b/cc/resources/tile_manager.cc
@@ -166,6 +166,7 @@ TileManager::TileManager(
       use_cheapness_estimator_(use_cheapness_estimator),
       use_color_estimator_(use_color_estimator),
       prediction_benchmarking_(prediction_benchmarking),
+      did_initialize_visible_tile_(false),
       pending_tasks_(0),
       max_pending_tasks_(kMaxNumPendingTasksPerThread * num_raster_threads),
       rendering_stats_instrumentation_(rendering_stats_instrumentation) {
@@ -437,6 +438,11 @@ void TileManager::ForceTileUploadToComplete(Tile* tile) {
     DidTileRasterStateChange(tile, FORCED_UPLOAD_COMPLETION_STATE);
     DidFinishTileInitialization(tile);
   }
+
+  if (did_initialize_visible_tile_) {
+    did_initialize_visible_tile_ = false;
+    client_->DidInitializeVisibleTile();
+  }
 }
 
 void TileManager::GetMemoryStats(
@@ -685,11 +691,16 @@ void TileManager::DispatchMoreTasks() {
       tiles_with_image_decoding_tasks_.push_back(tile);
     } else {
       if (!CanDispatchRasterTask(tile))
-        return;
+        break;
       DispatchOneRasterTask(tile);
     }
     tiles_that_need_to_be_rasterized_.pop_back();
   }
+
+  if (did_initialize_visible_tile_) {
+    did_initialize_visible_tile_ = false;
+    client_->DidInitializeVisibleTile();
+  }
 }
 
 void TileManager::AnalyzeTile(Tile* tile) {
@@ -925,7 +936,7 @@ void TileManager::OnRasterTaskCompleted(
 void TileManager::DidFinishTileInitialization(Tile* tile) {
   tile->drawing_info().resource_is_being_initialized_ = false;
   if (tile->priority(ACTIVE_TREE).distance_to_visible_in_pixels == 0)
-    client_->DidInitializeVisibleTile();
+    did_initialize_visible_tile_ = true;
 }
 
 void TileManager::DidTileRasterStateChange(Tile* tile, TileRasterState state) {
diff --git a/cc/resources/tile_manager.h b/cc/resources/tile_manager.h
index 105d2d6..1166c04 100644
--- a/cc/resources/tile_manager.h
+++ b/cc/resources/tile_manager.h
@@ -217,6 +217,7 @@ class CC_EXPORT TileManager : public WorkerPoolClient {
   bool use_color_estimator_;
   int raster_state_count_[NUM_STATES][NUM_TREES][NUM_BINS];
   bool prediction_benchmarking_;
+  bool did_initialize_visible_tile_;
 
   size_t pending_tasks_;
   size_t max_pending_tasks_;