cc: Use multiple PrepareTiles approaches

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 61253372be19003f42f111f0856321cc61acb389..5ad085c8aaf1925bd0e68289aab5db940385401e 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -321,7 +321,8 @@ void LayerTreeHostImpl::CommitComplete() {
     sync_tree()->UpdateDrawProperties(update_lcd_text);
     // Start working on newly created tiles immediately if needed.
     if (tile_manager_ && tile_priorities_dirty_) {
-      PrepareTiles();
+      bool for_commit = true;
+      client_->SetNeedsPrepareTilesOnImplThread(for_commit);
     } else {
       NotifyReadyToActivate();
 
@@ -410,8 +411,6 @@ void LayerTreeHostImpl::PrepareTiles() {
 
   tile_priorities_dirty_ = false;
   tile_manager_->PrepareTiles(global_tile_state_);
-
-  client_->DidPrepareTiles();
 }
 
 void LayerTreeHostImpl::StartPageScaleAnimation(
@@ -787,6 +786,7 @@ DrawResult LayerTreeHostImpl::CalculateRenderPasses(
 
   const DrawMode draw_mode = GetDrawMode();
 
+  int num_tiles_missing_raster_source = 0;
   int num_missing_tiles = 0;
   int num_incomplete_tiles = 0;
   bool have_copy_request = false;
@@ -869,10 +869,15 @@ DrawResult LayerTreeHostImpl::CalculateRenderPasses(
     rendering_stats_instrumentation_->AddCheckerboardedVisibleContentArea(
         append_quads_data.checkerboarded_visible_content_area);
 
+    num_tiles_missing_raster_source +=
+        append_quads_data.num_tiles_missing_raster_source;
     num_missing_tiles += append_quads_data.num_missing_tiles;
     num_incomplete_tiles += append_quads_data.num_incomplete_tiles;
 
     if (append_quads_data.num_missing_tiles) {
+      // TODO(brianderson): Figure out what to do in this case and
+      // differentiate and prioritize scroll wheel, touch scroll, and
+      // animations.
       bool layer_has_animating_transform =
           it->screen_space_transform_is_animating() ||
           it->draw_transform_is_animating();
@@ -881,24 +886,22 @@ DrawResult LayerTreeHostImpl::CalculateRenderPasses(
     }
   }
 
-  if (have_missing_animated_tiles)
-    draw_result = DRAW_ABORTED_CHECKERBOARD_ANIMATIONS;
-
-  // When we require high res to draw, abort the draw (almost) always. This does
-  // not cause the scheduler to do a main frame, instead it will continue to try
-  // drawing until we finally complete, so the copy request will not be lost.
-  // TODO(weiliangc): Remove RequiresHighResToDraw. crbug.com/469175
-  if (num_incomplete_tiles || num_missing_tiles) {
-    if (RequiresHighResToDraw())
-      draw_result = DRAW_ABORTED_MISSING_HIGH_RES_CONTENT;
-  }
-
-  // When this capability is set we don't have control over the surface the
-  // compositor draws to, so even though the frame may not be complete, the
-  // previous frame has already been potentially lost, so an incomplete frame is
-  // better than nothing, so this takes highest precidence.
-  if (output_surface_->capabilities().draw_and_swap_full_viewport_every_frame)
+  if (output_surface_->capabilities().draw_and_swap_full_viewport_every_frame) {
+    // When this capability is set we don't have control over the surface the
+    // compositor draws to, so even though the frame may not be complete, the
+    // previous frame has already been potentially lost, so an incomplete frame
+    // is
+    // better than nothing, so this takes highest precidence.
+    // TODO(brianderson): Use a forced draw instead of lying about the draw
+    // result.
     draw_result = DRAW_SUCCESS;
+  } else if (num_tiles_missing_raster_source) {
+    draw_result = DRAW_ABORTED_MISSING_RASTER_SOURCE;
+  } else if (num_missing_tiles) {
+    draw_result = DRAW_ABORTED_MISSING_RASTER_OUTPUT_ANY;
+  } else if (num_incomplete_tiles) {
+    draw_result = DRAW_ABORTED_MISSING_RASTER_OUTPUT_HIGH_RES;
+  }
 
 #if DCHECK_IS_ON()
   for (const auto& render_pass : frame->render_passes) {
@@ -1217,7 +1220,8 @@ void LayerTreeHostImpl::DidModifyTilePriorities() {
   DCHECK(settings_.impl_side_painting);
   // Mark priorities as dirty and schedule a PrepareTiles().
   tile_priorities_dirty_ = true;
-  client_->SetNeedsPrepareTilesOnImplThread();
+  bool for_commit = false;
+  client_->SetNeedsPrepareTilesOnImplThread(for_commit);
 }
 
 scoped_ptr<RasterTilePriorityQueue> LayerTreeHostImpl::BuildRasterQueue(
@@ -1633,7 +1637,7 @@ void LayerTreeHostImpl::UpdateGpuRasterizationStatus() {
   // We have released tilings for both active and pending tree.
   // We would not have any content to draw until the pending tree is activated.
   // Prevent the active tree from drawing until activation.
-  SetRequiresHighResToDraw();
+  SetRequiresHighResToDraw(true);
 }
 
 const RendererCapabilitiesImpl&
@@ -1643,7 +1647,7 @@ LayerTreeHostImpl::GetRendererCapabilities() const {
 }
 
 bool LayerTreeHostImpl::SwapBuffers(const LayerTreeHostImpl::FrameData& frame) {
-  ResetRequiresHighResToDraw();
+  SetRequiresHighResToDraw(false);
   if (frame.has_no_damage) {
     active_tree()->BreakSwapPromises(SwapPromise::SWAP_FAILS);
     return false;
@@ -1905,15 +1909,10 @@ void LayerTreeHostImpl::SetVisible(bool visible) {
   // If we just became visible, we have to ensure that we draw high res tiles,
   // to prevent checkerboard/low res flashes.
   if (visible_)
-    SetRequiresHighResToDraw();
+    SetRequiresHighResToDraw(true);
   else
     EvictAllUIResources();
 
-  // Evict tiles immediately if invisible since this tab may never get another
-  // draw or timer tick.
-  if (!visible_)
-    PrepareTiles();
-
   if (!renderer_)
     return;
 
@@ -2204,7 +2203,7 @@ bool LayerTreeHostImpl::InitializeRenderer(
   // There will not be anything to draw here, so set high res
   // to avoid checkerboards, typically when we are recovering
   // from lost context.
-  SetRequiresHighResToDraw();
+  SetRequiresHighResToDraw(true);
 
   return true;
 }