Improvements to uses of base::SmallMap

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/layer_tree_host_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1140 matching lines @@
   // If we return DRAW_SUCCESS, then we expect DrawLayers() to be called before
   // this function is called again.
   return draw_result;
 }
 
 void LayerTreeHostImpl::RemoveRenderPasses(FrameData* frame) {
   // There is always at least a root RenderPass.
   DCHECK_GE(frame->render_passes.size(), 1u);
 
   // A set of RenderPasses that we have seen.
   std::set<int> pass_exists;

[brettw, 2017/04/19 16:29:48]

We discussed in chat also changing this to a flat_set

   // A set of RenderPassDrawQuads that we have seen (stored by the RenderPasses
   // they refer to).
-  base::SmallMap<std::unordered_map<int, int>> pass_references;
+  base::small_map<std::unordered_map<int, int>> pass_references;

[danakj, 2017/04/18 21:35:50]

This should be a flat_map

 
   // Iterate RenderPasses in draw order, removing empty render passes (except
   // the root RenderPass).
   for (size_t i = 0; i < frame->render_passes.size(); ++i) {
     RenderPass* pass = frame->render_passes[i].get();
 
     // Remove orphan RenderPassDrawQuads.
     for (auto it = pass->quad_list.begin(); it != pass->quad_list.end();) {
       if (it->material != DrawQuad::RENDER_PASS) {
         ++it;
@@ skipping 3123 matching lines @@
 }
 
 void LayerTreeHostImpl::UpdateScrollSourceInfo(bool is_wheel_scroll) {
   if (is_wheel_scroll)
     has_scrolled_by_wheel_ = true;
   else
     has_scrolled_by_touch_ = true;
 }
 
 }  // namespace cc