Notify paint for each frame

third_party/WebKit/Source/platform/graphics/paint/PaintController.cpp

Index: third_party/WebKit/Source/platform/graphics/paint/PaintController.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/paint/PaintController.cpp b/third_party/WebKit/Source/platform/graphics/paint/PaintController.cpp
index c5ee0d2dcc69c2d3d5ab7f4d6cfc8b4a27faec58..66df222d3637b4bc464593c250fdde892fd6a992 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/PaintController.cpp
+++ b/third_party/WebKit/Source/platform/graphics/paint/PaintController.cpp
@@ -285,6 +285,16 @@ void PaintController::ProcessNewItem(DisplayItem& display_item) {
 
   if (RuntimeEnabledFeatures::paintUnderInvalidationCheckingEnabled())
     CheckUnderInvalidation();
+
+  if (!frame_first_paints_.back().first_painted && display_item.IsDrawing() &&

[Xianzhu, 2017/05/09 21:07:56]

PaintController might paint something before BeginFrame() (e.g. when
PaintController is used to paint an SVGImage), and back() will crash in the
case.

I think we can call BeginFrame(nullptr) from PaintController::PaintController()
to avoid the problem. (This will also enable us to combine the first paint data
in this PaintController into another PaintController on which we replay the
recorded result of this PaintController, in the future). 

[Zhen Wang, 2017/05/09 22:59:40]

Done.

+      // Here we ignore all document-background paintings because we don't
+      // know if the background is default. ViewPainter should have called
+      // setFirstPainted() if this display item is for non-default
+      // background.
+      display_item.GetType() != DisplayItem::kDocumentBackground &&
+      display_item.DrawsContent()) {
+    SetFirstPainted();
+  }
 }
 
 DisplayItem& PaintController::MoveItemFromCurrentListToNewList(size_t index) {
@@ -577,21 +587,6 @@ void PaintController::CommitNewDisplayItems(
     }
   }
 
-  if (!first_painted_) {
-    for (const auto& item : new_display_item_list_) {
-      if (item.IsDrawing() &&
-          // Here we ignore all document-background paintings because we don't
-          // know if the background is default. ViewPainter should have called
-          // setFirstPainted() if this display item is for non-default
-          // background.
-          item.GetType() != DisplayItem::kDocumentBackground &&
-          item.DrawsContent()) {
-        first_painted_ = true;
-        break;
-      }
-    }
-  }
-
   for (auto* client : skipped_cache_clients)
     client->SetDisplayItemsUncached();
 
@@ -944,4 +939,27 @@ void PaintController::ShowDebugDataInternal(bool show_paint_records) const {
           .data());
 }
 
+void PaintController::SetFirstPainted() {
+  frame_first_paints_.back().first_painted = true;
+}
+
+void PaintController::SetTextPainted() {
+  frame_first_paints_.back().text_painted = true;
+}
+
+void PaintController::SetImagePainted() {
+  frame_first_paints_.back().image_painted = true;
+}
+
+void PaintController::BeginFrame(const void* frame) {
+  frame_first_paints_.push_back(FrameFirstPaint(frame));
+}
+
+FrameFirstPaint PaintController::EndFrame(const void* frame) {
+  FrameFirstPaint result = frame_first_paints_.back();
+  DCHECK(result.frame == frame);
+  frame_first_paints_.pop_back();
+  return result;
+}
+
 }  // namespace blink