Update from https://crrev.com/304121

cc/resources/picture_pile_base.cc

-// Copyright 2013 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.
-
-#include "cc/resources/picture_pile_base.h"
-
-#include <algorithm>
-#include <set>
-#include <vector>
-
-#include "base/debug/trace_event_argument.h"
-#include "base/logging.h"
-#include "base/values.h"
-#include "cc/debug/traced_value.h"
-#include "third_party/skia/include/core/SkColor.h"
-#include "ui/gfx/geometry/rect_conversions.h"
-
-namespace {
-// Dimensions of the tiles in this picture pile as well as the dimensions of
-// the base picture in each tile.
-const int kBasePictureSize = 512;
-const int kTileGridBorderPixels = 1;
-#ifdef NDEBUG
-const bool kDefaultClearCanvasSetting = false;
-#else
-const bool kDefaultClearCanvasSetting = true;
-#endif
-
-// Invalidation frequency settings. kInvalidationFrequencyThreshold is a value
-// between 0 and 1 meaning invalidation frequency between 0% and 100% that
-// indicates when to stop invalidating offscreen regions.
-// kFrequentInvalidationDistanceThreshold defines what it means to be
-// "offscreen" in terms of distance to visible in css pixels.
-const float kInvalidationFrequencyThreshold = 0.75f;
-const int kFrequentInvalidationDistanceThreshold = 512;
-
-}  // namespace
-
-namespace cc {
-
-PicturePileBase::PicturePileBase()
-    : min_contents_scale_(0),
-      background_color_(SkColorSetARGBInline(0, 0, 0, 0)),
-      slow_down_raster_scale_factor_for_debug_(0),
-      contents_opaque_(false),
-      contents_fill_bounds_completely_(false),
-      show_debug_picture_borders_(false),
-      clear_canvas_with_debug_color_(kDefaultClearCanvasSetting),
-      has_any_recordings_(false),
-      is_mask_(false),
-      is_solid_color_(false),
-      solid_color_(SK_ColorTRANSPARENT) {
-  tiling_.SetMaxTextureSize(gfx::Size(kBasePictureSize, kBasePictureSize));
-  tile_grid_info_.fTileInterval.setEmpty();
-  tile_grid_info_.fMargin.setEmpty();
-  tile_grid_info_.fOffset.setZero();
-}
-
-PicturePileBase::PicturePileBase(const PicturePileBase* other)
-    : picture_map_(other->picture_map_),
-      tiling_(other->tiling_),
-      recorded_viewport_(other->recorded_viewport_),
-      min_contents_scale_(other->min_contents_scale_),
-      tile_grid_info_(other->tile_grid_info_),
-      background_color_(other->background_color_),
-      slow_down_raster_scale_factor_for_debug_(
-          other->slow_down_raster_scale_factor_for_debug_),
-      contents_opaque_(other->contents_opaque_),
-      contents_fill_bounds_completely_(other->contents_fill_bounds_completely_),
-      show_debug_picture_borders_(other->show_debug_picture_borders_),
-      clear_canvas_with_debug_color_(other->clear_canvas_with_debug_color_),
-      has_any_recordings_(other->has_any_recordings_),
-      is_mask_(other->is_mask_),
-      is_solid_color_(other->is_solid_color_),
-      solid_color_(other->solid_color_) {
-}
-
-PicturePileBase::~PicturePileBase() {
-}
-
-void PicturePileBase::SetMinContentsScale(float min_contents_scale) {
-  DCHECK(min_contents_scale);
-  if (min_contents_scale_ == min_contents_scale)
-    return;
-
-  // Picture contents are played back scaled. When the final contents scale is
-  // less than 1 (i.e. low res), then multiple recorded pixels will be used
-  // to raster one final pixel.  To avoid splitting a final pixel across
-  // pictures (which would result in incorrect rasterization due to blending), a
-  // buffer margin is added so that any picture can be snapped to integral
-  // final pixels.
-  //
-  // For example, if a 1/4 contents scale is used, then that would be 3 buffer
-  // pixels, since that's the minimum number of pixels to add so that resulting
-  // content can be snapped to a four pixel aligned grid.
-  int buffer_pixels = static_cast<int>(ceil(1 / min_contents_scale) - 1);
-  buffer_pixels = std::max(0, buffer_pixels);
-  SetBufferPixels(buffer_pixels);
-  min_contents_scale_ = min_contents_scale;
-}
-
-// static
-void PicturePileBase::ComputeTileGridInfo(
-    const gfx::Size& tile_grid_size,
-    SkTileGridFactory::TileGridInfo* info) {
-  DCHECK(info);
-  info->fTileInterval.set(tile_grid_size.width() - 2 * kTileGridBorderPixels,
-                          tile_grid_size.height() - 2 * kTileGridBorderPixels);
-  DCHECK_GT(info->fTileInterval.width(), 0);
-  DCHECK_GT(info->fTileInterval.height(), 0);
-  info->fMargin.set(kTileGridBorderPixels, kTileGridBorderPixels);
-  // Offset the tile grid coordinate space to take into account the fact
-  // that the top-most and left-most tiles do not have top and left borders
-  // respectively.
-  info->fOffset.set(-kTileGridBorderPixels, -kTileGridBorderPixels);
-}
-
-void PicturePileBase::SetTileGridSize(const gfx::Size& tile_grid_size) {
-  ComputeTileGridInfo(tile_grid_size, &tile_grid_info_);
-}
-
-void PicturePileBase::SetBufferPixels(int new_buffer_pixels) {
-  if (new_buffer_pixels == buffer_pixels())
-    return;
-
-  Clear();
-  tiling_.SetBorderTexels(new_buffer_pixels);
-}
-
-void PicturePileBase::Clear() {
-  picture_map_.clear();
-  recorded_viewport_ = gfx::Rect();
-  has_any_recordings_ = false;
-  is_solid_color_ = false;
-}
-
-bool PicturePileBase::HasRecordingAt(int x, int y) {
-  PictureMap::const_iterator found = picture_map_.find(PictureMapKey(x, y));
-  if (found == picture_map_.end())
-    return false;
-  return !!found->second.GetPicture();
-}
-
-bool PicturePileBase::CanRaster(float contents_scale,
-                                const gfx::Rect& content_rect) const {
-  if (tiling_.tiling_size().IsEmpty())
-    return false;
-  gfx::Rect layer_rect = gfx::ScaleToEnclosingRect(
-      content_rect, 1.f / contents_scale);
-  layer_rect.Intersect(gfx::Rect(tiling_.tiling_size()));
-
-  // Common case inside of viewport to avoid the slower map lookups.
-  if (recorded_viewport_.Contains(layer_rect)) {
-    // Sanity check that there are no false positives in recorded_viewport_.
-    DCHECK(CanRasterSlowTileCheck(layer_rect));
-    return true;
-  }
-
-  return CanRasterSlowTileCheck(layer_rect);
-}
-
-bool PicturePileBase::CanRasterSlowTileCheck(
-    const gfx::Rect& layer_rect) const {
-  bool include_borders = false;
-  for (TilingData::Iterator tile_iter(&tiling_, layer_rect, include_borders);
-       tile_iter;
-       ++tile_iter) {
-    PictureMap::const_iterator map_iter = picture_map_.find(tile_iter.index());
-    if (map_iter == picture_map_.end())
-      return false;
-    if (!map_iter->second.GetPicture())
-      return false;
-  }
-  return true;
-}
-
-gfx::Rect PicturePileBase::PaddedRect(const PictureMapKey& key) const {
-  gfx::Rect tile = tiling_.TileBounds(key.first, key.second);
-  return PadRect(tile);
-}
-
-gfx::Rect PicturePileBase::PadRect(const gfx::Rect& rect) const {
-  gfx::Rect padded_rect = rect;
-  padded_rect.Inset(
-      -buffer_pixels(), -buffer_pixels(), -buffer_pixels(), -buffer_pixels());
-  return padded_rect;
-}
-
-void PicturePileBase::AsValueInto(base::debug::TracedValue* pictures) const {
-  gfx::Rect tiling_rect(tiling_.tiling_size());
-  std::set<const void*> appended_pictures;
-  bool include_borders = true;
-  for (TilingData::Iterator tile_iter(&tiling_, tiling_rect, include_borders);
-       tile_iter;
-       ++tile_iter) {
-    PictureMap::const_iterator map_iter = picture_map_.find(tile_iter.index());
-    if (map_iter == picture_map_.end())
-      continue;
-
-    const Picture* picture = map_iter->second.GetPicture();
-    if (picture && (appended_pictures.count(picture) == 0)) {
-      appended_pictures.insert(picture);
-      TracedValue::AppendIDRef(picture, pictures);
-    }
-  }
-}
-
-PicturePileBase::PictureInfo::PictureInfo() : last_frame_number_(0) {}
-
-PicturePileBase::PictureInfo::~PictureInfo() {}
-
-void PicturePileBase::PictureInfo::AdvanceInvalidationHistory(
-    int frame_number) {
-  DCHECK_GE(frame_number, last_frame_number_);
-  if (frame_number == last_frame_number_)
-    return;
-
-  invalidation_history_ <<= (frame_number - last_frame_number_);
-  last_frame_number_ = frame_number;
-}
-
-bool PicturePileBase::PictureInfo::Invalidate(int frame_number) {
-  AdvanceInvalidationHistory(frame_number);
-  invalidation_history_.set(0);
-
-  bool did_invalidate = !!picture_.get();
-  picture_ = NULL;
-  return did_invalidate;
-}
-
-bool PicturePileBase::PictureInfo::NeedsRecording(int frame_number,
-                                                  int distance_to_visible) {
-  AdvanceInvalidationHistory(frame_number);
-
-  // We only need recording if we don't have a picture. Furthermore, we only
-  // need a recording if we're within frequent invalidation distance threshold
-  // or the invalidation is not frequent enough (below invalidation frequency
-  // threshold).
-  return !picture_.get() &&
-         ((distance_to_visible <= kFrequentInvalidationDistanceThreshold) ||
-          (GetInvalidationFrequency() < kInvalidationFrequencyThreshold));
-}
-
-void PicturePileBase::PictureInfo::SetPicture(scoped_refptr<Picture> picture) {
-  picture_ = picture;
-}
-
-const Picture* PicturePileBase::PictureInfo::GetPicture() const {
-  return picture_.get();
-}
-
-float PicturePileBase::PictureInfo::GetInvalidationFrequency() const {
-  return invalidation_history_.count() /
-         static_cast<float>(INVALIDATION_FRAMES_TRACKED);
-}
-
-}  // namespace cc