Add protobuf serialization to DisplayItemList

cc/playback/display_item_list.cc

Index: cc/playback/display_item_list.cc
diff --git a/cc/playback/display_item_list.cc b/cc/playback/display_item_list.cc
index 7614bfd8a2fc81a5fcaf2e783e98b5572f05e13e..c34a53c705d7cdba11f5f41b2014341adefb8f99 100644
--- a/cc/playback/display_item_list.cc
+++ b/cc/playback/display_item_list.cc
@@ -14,7 +14,10 @@
 #include "cc/debug/traced_display_item_list.h"
 #include "cc/debug/traced_value.h"
 #include "cc/playback/display_item_list_settings.h"
+#include "cc/playback/display_item_proto_factory.h"
 #include "cc/playback/largest_display_item.h"
+#include "cc/proto/display_item.pb.h"
+#include "cc/proto/gfx_conversions.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkPictureRecorder.h"
 #include "third_party/skia/include/utils/SkPictureUtils.h"
@@ -47,11 +50,29 @@ scoped_refptr<DisplayItemList> DisplayItemList::Create(
       !settings.use_cached_picture || DisplayItemsTracingEnabled()));
 }
 
+scoped_refptr<DisplayItemList> DisplayItemList::CreateFromProto(
+    const proto::DisplayItemList& proto) {
+  gfx::Rect layer_rect = ProtoToRect(proto.layer_rect());

[vmpstr, 2015/10/27 21:49:47]

As a separate thing, can you file a bug and/or a todo to put ProtoToRect and
friends into some class and make them static (or put them in some namespace).
I'd prefer to see where this function is coming from more or less... like for
example we have MathUtil and there we have like MathUtil::Deg2Rad, etc.. it's a
bit clearer for me.

[David Trainor- moved to gerrit, 2015/10/27 22:49:23]

Yeah I can do that.  I was trying to be consistent with the existing gfx helper
methods (rect_conversions, point_conversions).  When I fix the bug not allowing
me to put proto files in different directories I plan on migrating all of these
to their rightful places too (gfx:: or skia::).

+  scoped_refptr<DisplayItemList> list =
+      DisplayItemList::Create(ProtoToRect(proto.layer_rect()),
+                              DisplayItemListSettings(proto.settings()));

[vmpstr, 2015/10/27 21:49:47]

There's some work to remove the cached_picture path, which would make the
display item list settings empty. Would it be a straight-forward patch to remove
it?

[David Trainor- moved to gerrit, 2015/10/27 22:49:23]

Yeah it would just be deleting the .proto file when we delete the
display_item_list_settings.cc/.h files (and the unit test/reference in the
display_item_list message).

+
+  for (int i = 0; i < proto.items_size(); i++) {
+    const proto::DisplayItem& item_proto = proto.items(i);
+    DisplayItem* item =
+        DisplayItemProtoFactory::AllocateAndConstruct(list, item_proto);
+    if (item)
+      item->FromProtobuf(item_proto);
+  }
+
+  return list;
+}
+
 DisplayItemList::DisplayItemList(gfx::Rect layer_rect,
                                  const DisplayItemListSettings& settings,
                                  bool retain_individual_display_items)
     : items_(LargestDisplayItemSize(), kDefaultNumDisplayItemsToReserve),
-      use_cached_picture_(settings.use_cached_picture),
+      settings_(settings),
       retain_individual_display_items_(retain_individual_display_items),
       layer_rect_(layer_rect),
       is_suitable_for_gpu_rasterization_(true),
@@ -61,7 +82,7 @@ DisplayItemList::DisplayItemList(gfx::Rect layer_rect,
 #if DCHECK_IS_ON()
   needs_process_ = false;
 #endif
-  if (use_cached_picture_) {
+  if (settings_.use_cached_picture) {
     SkRTreeFactory factory;
     recorder_.reset(new SkPictureRecorder());
     canvas_ = skia::SharePtr(recorder_->beginRecording(
@@ -74,12 +95,22 @@ DisplayItemList::DisplayItemList(gfx::Rect layer_rect,
 DisplayItemList::~DisplayItemList() {
 }
 
+void DisplayItemList::ToProtobuf(proto::DisplayItemList* proto) {
+  // TODO(dtrainor): Send only changed state.

[vmpstr, 2015/10/27 21:49:47]

Can you file a bug and put a reference to it here?

[David Trainor- moved to gerrit, 2015/10/27 22:49:23]

Removed TODO.  Put bug number in the header file TODO which basically says the
same thing.

+  RectToProto(layer_rect_, proto->mutable_layer_rect());
+  settings_.ToProtobuf(proto->mutable_settings());
+
+  DCHECK_EQ(0, proto->items_size());
+  for (auto* item : items_)
+    item->ToProtobuf(proto->add_items());
+}
+
 void DisplayItemList::Raster(SkCanvas* canvas,
                              SkPicture::AbortCallback* callback,
                              const gfx::Rect& canvas_target_playback_rect,
                              float contents_scale) const {
   DCHECK(ProcessAppendedItemsCalled());
-  if (!use_cached_picture_) {
+  if (!settings_.use_cached_picture) {
     canvas->save();
     canvas->scale(contents_scale, contents_scale);
     for (auto* item : items_)
@@ -122,7 +153,7 @@ void DisplayItemList::ProcessAppendedItems() {
   needs_process_ = false;
 #endif
   for (const DisplayItem* item : items_) {
-    if (use_cached_picture_) {
+    if (settings_.use_cached_picture) {
       // When using a cached picture we will calculate gpu suitability on the
       // entire cached picture instead of the items. This is more permissive
       // since none of the items might individually trigger a veto even though
@@ -165,16 +196,16 @@ void DisplayItemList::RemoveLast() {
   // The last item should not have been handled by ProcessAppendedItems, so we
   // don't need to remove it from approximate_op_count_, etc.
   DCHECK(retain_individual_display_items_);
-  DCHECK(!use_cached_picture_);
+  DCHECK(!settings_.use_cached_picture);
   items_.RemoveLast();
 }
 
 void DisplayItemList::Finalize() {
   ProcessAppendedItems();
 
-  if (use_cached_picture_) {
+  if (settings_.use_cached_picture) {
     // Convert to an SkPicture for faster rasterization.
-    DCHECK(use_cached_picture_);
+    DCHECK(settings_.use_cached_picture);
     DCHECK(!picture_);
     picture_ = skia::AdoptRef(recorder_->endRecordingAsPicture());
     DCHECK(picture_);
@@ -200,10 +231,10 @@ int DisplayItemList::ApproximateOpCount() const {
 size_t DisplayItemList::ApproximateMemoryUsage() const {
   DCHECK(ProcessAppendedItemsCalled());
   // We double-count in this case. Produce zero to avoid being misleading.
-  if (use_cached_picture_ && retain_individual_display_items_)
+  if (settings_.use_cached_picture && retain_individual_display_items_)
     return 0;
 
-  DCHECK_IMPLIES(use_cached_picture_, picture_);
+  DCHECK_IMPLIES(settings_.use_cached_picture, picture_);
 
   size_t memory_usage = sizeof(*this);
 
@@ -273,8 +304,8 @@ void DisplayItemList::GenerateDiscardableImagesMetadata() {
   DCHECK(ProcessAppendedItemsCalled());
   // This should be only called once, and only after CreateAndCacheSkPicture.
   DCHECK(image_map_.empty());
-  DCHECK_IMPLIES(use_cached_picture_, picture_);
-  if (use_cached_picture_ && !picture_->willPlayBackBitmaps())
+  DCHECK_IMPLIES(settings_.use_cached_picture, picture_);
+  if (settings_.use_cached_picture && !picture_->willPlayBackBitmaps())
     return;
 
   // The cached picture is translated by -layer_rect_.origin during record,