Introduce ui::PaintRecorder and use it for CursorWindowDelegate.

ui/views/view.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #define _USE_MATH_DEFINES // For VC++ to get M_PI. This has to be first.
 
 #include "ui/views/view.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/trace_event/trace_event.h"
 #include "cc/resources/display_item_list.h"
 #include "cc/resources/drawing_display_item.h"
-#include "third_party/skia/include/core/SkPictureRecorder.h"
 #include "third_party/skia/include/core/SkRect.h"
 #include "ui/accessibility/ax_enums.h"
 #include "ui/base/cursor/cursor.h"
 #include "ui/base/dragdrop/drag_drop_types.h"
 #include "ui/compositor/compositor.h"
 #include "ui/compositor/dip_util.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_animator.h"
+#include "ui/compositor/paint_recorder.h"
 #include "ui/events/event_target_iterator.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/geometry/point3_f.h"
 #include "ui/gfx/geometry/point_conversions.h"
 #include "ui/gfx/interpolated_transform.h"
 #include "ui/gfx/path.h"
 #include "ui/gfx/scoped_canvas.h"
 #include "ui/gfx/screen.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/gfx/transform.h"
@@ skipping 1418 matching lines @@
     SetLayerBounds(GetLocalBounds() + offset);
   } else {
     for (int i = 0, count = child_count(); i < count; ++i) {
       View* child = child_at(i);
       child->UpdateChildLayerBounds(
           offset + gfx::Vector2d(child->GetMirroredX(), child->y()));
     }
   }
 }
 
 void View::OnPaintLayerToDisplayList(cc::DisplayItemList* list,

[sky, 2015/03/20 14:52:45]

I was commenting on this function. This hasn't landed in master yet, which is
why I find this patch a bit confusing.

[danakj, 2015/03/20 15:26:35]

Ya this patch depends on the first one to add the functions. I changed this
function here just to demonstrate that both views (caching) and other (non
caching) can both share code by using the paint recorder. 

This shouldn't make the views implementation here any more complete yet. 

                                      float device_scale_factor) {
   TRACE_EVENT1("views", "View::OnPaintToDisplayList", "class", GetClassName());
 
+  // TODO(danakj): Instead of always recording, cache a picture in each view and
+  // reuse it when not invalidated. ie. just AppendItem() and return here.
+
   // TODO(danakj): Does this include the bounds of all children?
   // TODO(danakj): Should this be the layer's bounds?
+  // TODO(danakj): The paint code does transforms on the canvas to position
+  // children, but each DisplayItem's recording bounds and origin should be
+  // relative to the layer, I think.
   gfx::Rect view_bounds = GetLocalBounds();
 
-  // TODO(danakj): Instead of always recording, cache a picture in each view and
-  // reuse it when not invalidated.
-  SkPictureRecorder recorder;
-  SkRTreeFactory* no_factory = nullptr;
-  skia::RefPtr<SkCanvas> skcanvas = skia::SharePtr(recorder.beginRecording(
-      view_bounds.width(), view_bounds.height(), no_factory,
-      SkPictureRecorder::kComputeSaveLayerInfo_RecordFlag));
-  skcanvas->clipRect(gfx::RectToSkRect(view_bounds));
+  ui::PaintRecorder recorder(view_bounds, device_scale_factor);
+  OnPaintLayer(recorder.canvas());
 
-  {
-    scoped_ptr<gfx::Canvas> canvas(gfx::Canvas::CreateCanvasWithoutScaling(
-        skcanvas.get(), device_scale_factor));
-    if (!layer() || !layer()->fills_bounds_opaquely())
-      canvas->DrawColor(SK_ColorBLACK, SkXfermode::kClear_Mode);
-    PaintCommon(canvas.get(), CullSet());
-  }
-
-  skia::RefPtr<SkPicture> picture = skia::AdoptRef(recorder.endRecording());
-  scoped_ptr<cc::DrawingDisplayItem> item =
-      cc::DrawingDisplayItem::Create(picture);
-  list->AppendItem(item.Pass());
+  // TODO(danakj): Cache this picture in the View and reuse it.
+  scoped_ptr<cc::DrawingDisplayItem> item = recorder.TakeDisplayItem();
+  list->AppendItem(item->Clone());
 }
 
 void View::OnPaintLayer(gfx::Canvas* canvas) {
   if (!layer() || !layer()->fills_bounds_opaquely())
     canvas->DrawColor(SK_ColorBLACK, SkXfermode::kClear_Mode);
   PaintCommon(canvas, CullSet());
 }
 
 void View::OnDelegatedFrameDamage(
     const gfx::Rect& damage_rect_in_dip) {
@@ skipping 1001 matching lines @@
   // Message the RootView to do the drag and drop. That way if we're removed
   // the RootView can detect it and avoid calling us back.
   gfx::Point widget_location(event.location());
   ConvertPointToWidget(this, &widget_location);
   widget->RunShellDrag(this, data, widget_location, drag_operations, source);
   // WARNING: we may have been deleted.
   return true;
 }
 
 }  // namespace views