cc: Fix serialization of display item lists

Display item lists currently don't support serializing flattened
pictures.  The tests magically got around this by waiting to "finalize"
the list until after serialization (which would have cleared the display
items) and never having enough items serialized to cause on-the-fly
flattening (which also would have cleared).

This patch moves the finalization to the place where this bug would have
been exposed and just dchecks that if somebody tries to serialize a
display item list that the display items have been retained, and updates
the unit tests to all do that so they pass.

R=dtrainor@chromium.org
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1494673003

Cr-Commit-Position: refs/heads/master@{#362870}

2 files changed, 6 insertions, 8 deletions

diff --git a/cc/playback/display_item_list.cc b/cc/playback/display_item_list.cc
index 5b0009a..a1a9cdb 100644
--- a/cc/playback/display_item_list.cc
+++ b/cc/playback/display_item_list.cc
@@ -99,6 +99,10 @@ DisplayItemList::~DisplayItemList() {
 }
 
 void DisplayItemList::ToProtobuf(proto::DisplayItemList* proto) {
+  // The flattened SkPicture approach is going away, and the proto
+  // doesn't currently support serializing that flattened picture.
+  DCHECK(retain_individual_display_items_);
+
   RectToProto(layer_rect_, proto->mutable_layer_rect());
   settings_.ToProtobuf(proto->mutable_settings());
 
diff --git a/cc/playback/display_item_list_unittest.cc b/cc/playback/display_item_list_unittest.cc
index c2d2b43..b29baa3 100644
--- a/cc/playback/display_item_list_unittest.cc
+++ b/cc/playback/display_item_list_unittest.cc
@@ -76,6 +76,8 @@ void AppendSecondSerializationTestPicture(scoped_refptr<DisplayItemList> list,
 
 void ValidateDisplayItemListSerialization(const gfx::Size& layer_size,
                                           scoped_refptr<DisplayItemList> list) {
+  list->Finalize();
+
   // Serialize and deserialize the DisplayItemList.
   proto::DisplayItemList proto;
   list->ToProtobuf(&proto);
@@ -83,7 +85,6 @@ void ValidateDisplayItemListSerialization(const gfx::Size& layer_size,
       DisplayItemList::CreateFromProto(proto);
 
   // Finalize the DisplayItemLists to perform raster.
-  list->Finalize();
   new_list->Finalize();
 
   const int pixel_size = 4 * layer_size.GetArea();
@@ -127,7 +128,6 @@ TEST(DisplayItemListTest, SerializeSingleDrawingItem) {
   gfx::Size layer_size(10, 10);
 
   DisplayItemListSettings settings;
-  settings.use_cached_picture = true;
   scoped_refptr<DisplayItemList> list =
       DisplayItemList::Create(gfx::Rect(layer_size), settings);
 
@@ -141,7 +141,6 @@ TEST(DisplayItemListTest, SerializeClipItem) {
   gfx::Size layer_size(10, 10);
 
   DisplayItemListSettings settings;
-  settings.use_cached_picture = true;
   scoped_refptr<DisplayItemList> list =
       DisplayItemList::Create(gfx::Rect(layer_size), settings);
 
@@ -168,7 +167,6 @@ TEST(DisplayItemListTest, SerializeClipPathItem) {
   gfx::Size layer_size(10, 10);
 
   DisplayItemListSettings settings;
-  settings.use_cached_picture = true;
   scoped_refptr<DisplayItemList> list =
       DisplayItemList::Create(gfx::Rect(layer_size), settings);
 
@@ -194,7 +192,6 @@ TEST(DisplayItemListTest, SerializeCompositingItem) {
   gfx::Size layer_size(10, 10);
 
   DisplayItemListSettings settings;
-  settings.use_cached_picture = true;
   scoped_refptr<DisplayItemList> list =
       DisplayItemList::Create(gfx::Rect(layer_size), settings);
 
@@ -220,7 +217,6 @@ TEST(DisplayItemListTest, SerializeFloatClipItem) {
   gfx::Size layer_size(10, 10);
 
   DisplayItemListSettings settings;
-  settings.use_cached_picture = true;
   scoped_refptr<DisplayItemList> list =
       DisplayItemList::Create(gfx::Rect(layer_size), settings);
 
@@ -245,7 +241,6 @@ TEST(DisplayItemListTest, SerializeTransformItem) {
   gfx::Size layer_size(10, 10);
 
   DisplayItemListSettings settings;
-  settings.use_cached_picture = true;
   scoped_refptr<DisplayItemList> list =
       DisplayItemList::Create(gfx::Rect(layer_size), settings);
 
@@ -279,7 +274,6 @@ TEST(DisplayItemListTest, SingleDrawingItem) {
   red_paint.setColor(SK_ColorRED);
   unsigned char pixels[4 * 100 * 100] = {0};
   DisplayItemListSettings settings;
-  settings.use_cached_picture = true;
   scoped_refptr<DisplayItemList> list =
       DisplayItemList::Create(layer_rect, settings);