Overscroll and Elasticity for views::ScrollView

cc/trees/tree_synchronizer_unittest.cc

Index: cc/trees/tree_synchronizer_unittest.cc
diff --git a/cc/trees/tree_synchronizer_unittest.cc b/cc/trees/tree_synchronizer_unittest.cc
index f656634636a169d33a73916a3c430a072cc037ee..cf56de38d10b324b93dc1119c73d17cfad3691f9 100644
--- a/cc/trees/tree_synchronizer_unittest.cc
+++ b/cc/trees/tree_synchronizer_unittest.cc
@@ -130,15 +130,16 @@ class TreeSynchronizerTest : public testing::Test {
   TreeSynchronizerTest()
       : host_(FakeLayerTreeHost::Create(&client_, &task_graph_runner_)) {}
 
-  bool is_equal(ScrollTree::ScrollOffsetMap map,
-                ScrollTree::ScrollOffsetMap other) {
+  bool is_equal(const ScrollTree::ScrollOffsetMap& map,
+                const ScrollTree::ScrollOffsetMap& other) {
     if (map.size() != other.size())
       return false;
-    for (auto& map_entry : map) {
-      if (other.find(map_entry.first) == other.end())
+    for (const auto& map_entry : map) {
+      auto other_found = other.find(map_entry.first);
+      if (other_found == other.end())
         return false;
-      SyncedScrollOffset& from_map = *map_entry.second.get();
-      SyncedScrollOffset& from_other = *other[map_entry.first].get();
+      SyncedScrollOffset& from_map = *map_entry.second.synced_offset.get();
+      SyncedScrollOffset& from_other = *other_found->second.synced_offset.get();
       if (from_map.PendingBase() != from_other.PendingBase() ||
           from_map.ActiveBase() != from_other.ActiveBase() ||
           from_map.Delta() != from_other.Delta() ||
@@ -566,18 +567,20 @@ TEST_F(TreeSynchronizerTest, SynchronizeScrollTreeScrollOffsetMap) {
   // have one entry for scroll_layer and one entry for transient_scroll_layer,
   // the pending base and active base must be the same at this stage.
   ScrollTree::ScrollOffsetMap scroll_offset_map;
-  scroll_offset_map[scroll_layer->id()] = new SyncedScrollOffset;
-  scroll_offset_map[transient_scroll_layer->id()] = new SyncedScrollOffset;
-  scroll_offset_map[scroll_layer->id()]->PushFromMainThread(
-      scroll_layer->scroll_offset());
-  scroll_offset_map[scroll_layer->id()]->PushPendingToActive();
-  scroll_offset_map[transient_scroll_layer->id()]->PushFromMainThread(
-      transient_scroll_layer->scroll_offset());
-  scroll_offset_map[transient_scroll_layer->id()]->PushPendingToActive();
-  EXPECT_TRUE(
-      is_equal(scroll_offset_map, host_impl->active_tree()
-                                      ->property_trees()
-                                      ->scroll_tree.scroll_offset_map()));
+  auto& scroll_offset = scroll_offset_map[scroll_layer->id()].synced_offset;
+  auto& transient_offset =
+      scroll_offset_map[transient_scroll_layer->id()].synced_offset;
+
+  scroll_offset = new SyncedScrollOffset;
+  transient_offset = new SyncedScrollOffset;
+  scroll_offset->PushFromMainThread(scroll_layer->scroll_offset());
+  scroll_offset->PushPendingToActive();
+  transient_offset->PushFromMainThread(transient_scroll_layer->scroll_offset());
+  transient_offset->PushPendingToActive();
+  EXPECT_TRUE(is_equal(scroll_offset_map,
+                       host_impl->active_tree()
+                           ->property_trees()
+                           ->scroll_tree.scroll_offset_map_for_test()));
 
   // Set ScrollOffset active delta: gfx::ScrollOffset(10, 10)
   LayerImpl* scroll_layer_impl =
@@ -611,13 +614,14 @@ TEST_F(TreeSynchronizerTest, SynchronizeScrollTreeScrollOffsetMap) {
   EXPECT_EQ(scroll_layer->id(),
             host_impl->active_tree()->CurrentlyScrollingLayer()->id());
   scroll_offset_map.erase(transient_scroll_layer->id());
-  scroll_offset_map[scroll_layer->id()]->SetCurrent(gfx::ScrollOffset(20, 30));
-  scroll_offset_map[scroll_layer->id()]->PullDeltaForMainThread();
-  scroll_offset_map[scroll_layer->id()]->SetCurrent(gfx::ScrollOffset(40, 50));
-  scroll_offset_map[scroll_layer->id()]->PushFromMainThread(
-      gfx::ScrollOffset(100, 100));
-  scroll_offset_map[scroll_layer->id()]->PushPendingToActive();
-  EXPECT_TRUE(is_equal(scroll_offset_map, scroll_tree.scroll_offset_map()));
+  scroll_offset = scroll_offset_map[scroll_layer->id()].synced_offset;
+  scroll_offset->SetCurrent(gfx::ScrollOffset(20, 30));
+  scroll_offset->PullDeltaForMainThread();
+  scroll_offset->SetCurrent(gfx::ScrollOffset(40, 50));
+  scroll_offset->PushFromMainThread(gfx::ScrollOffset(100, 100));
+  scroll_offset->PushPendingToActive();
+  EXPECT_TRUE(
+      is_equal(scroll_offset_map, scroll_tree.scroll_offset_map_for_test()));
 }
 
 TEST_F(TreeSynchronizerTest, RefreshPropertyTreesCachedData) {