Reserve space in the resource ID set.

cc/surfaces/surface_aggregator.cc

Index: cc/surfaces/surface_aggregator.cc
diff --git a/cc/surfaces/surface_aggregator.cc b/cc/surfaces/surface_aggregator.cc
index b4123d01d48c3c376d6f7a19dd2ccd741c4dcab7..1f645f238c2f73ec65f3d585767adaf4c9bf95ac 100644
--- a/cc/surfaces/surface_aggregator.cc
+++ b/cc/surfaces/surface_aggregator.cc
@@ -170,6 +170,15 @@ bool SurfaceAggregator::ValidateResources(
   provider_->ReceiveFromChild(child_id, frame_data->resource_list);
 
   ResourceProvider::ResourceIdSet referenced_resources;
+  size_t reserve_size =
+      std::max(static_cast<size_t>(1), frame_data->resource_list.size());

[danakj, 2015/04/25 17:16:44]

why the Max 1?

+#if defined(COMPILER_MSVC)
+  referenced_resources.reserve(reserve_size);
+#elif defined(COMPILER_GCC)
+  // Pre-standard hash-tables only implement resize, which behaves similarly

[danakj, 2015/04/25 17:16:44]

wow really? I'm surprised this is all we have in our toolchain. leave a TODO to
fix this with c++11?

can we do similar in DRLI too? that's affect children who don't use surfaces yet
(pdf viewer seems to be one eg)

+  // to reserve for these keys.
+  referenced_resources.resize(reserve_size);
+#endif
 
   bool invalid_frame = false;
   DrawQuad::ResourceIteratorCallback remap =