cc: Apply contents scales to impl-side painting rasterization

Tiles now have a contents scale that they are rastered with, so that non-1.0
contents scales work.  Additionally, PictureLayer derives from
ContentsScalingLayer so that it picks up the right content bounds and default
contents scale.

BUG=155209


Review URL: https://chromiumcodereview.appspot.com/11421210

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@171111 0039d316-1c4b-4281-b951-d872f2087c98

cc/picture_layer.h

@@ -5,6 +5,7 @@
 #ifndef CC_PICTURE_LAYER_H_
 #define CC_PICTURE_LAYER_H_
 
+#include "cc/contents_scaling_layer.h"
 #include "cc/layer.h"
 #include "cc/picture_pile.h"
 #include "cc/occlusion_tracker.h"
@@ -15,7 +16,7 @@ class ContentLayerClient;
 class ResourceUpdateQueue;
 struct RenderingStats;
 
-class CC_EXPORT PictureLayer : public Layer {
+class CC_EXPORT PictureLayer : public ContentsScalingLayer {
 public:
   static scoped_refptr<PictureLayer> create(ContentLayerClient*);
 

cc/picture_layer_impl.cc

@@ -160,7 +160,7 @@ void PictureLayerImpl::didUpdateTransforms() {
   last_content_scale_y_ = contentsScaleY();
 }
 
-scoped_refptr<Tile> PictureLayerImpl::CreateTile(PictureLayerTiling*,
+scoped_refptr<Tile> PictureLayerImpl::CreateTile(PictureLayerTiling* tiling,
                                                  gfx::Rect rect) {
   TileManager* tile_manager = layerTreeHostImpl()->tileManager();
 
@@ -169,7 +169,8 @@ scoped_refptr<Tile> PictureLayerImpl::CreateTile(PictureLayerTiling*,
       pile_.get(),
       rect.size(),
       GL_RGBA,
-      rect));
+      rect,
+      tiling->contents_scale()));
 }
 
 void PictureLayerImpl::SyncFromActiveLayer(const PictureLayerImpl* other) {

cc/picture_pile_impl.cc

@@ -30,8 +30,11 @@ scoped_refptr<PicturePileImpl> PicturePileImpl::CloneForDrawing() const {
   return clone;
 }
 
-void PicturePileImpl::Raster(SkCanvas* canvas, gfx::Rect rect,
-                             RenderingStats* stats) {
+void PicturePileImpl::Raster(
+    SkCanvas* canvas,
+    gfx::Rect rect,
+    float contents_scale,
+    RenderingStats* stats) {
   base::TimeTicks rasterizeBeginTime = base::TimeTicks::Now();
 
   // TODO(enne): do this more efficiently, i.e. top down with Skia clips
@@ -40,6 +43,7 @@ void PicturePileImpl::Raster(SkCanvas* canvas, gfx::Rect rect,
   SkRect layer_skrect = SkRect::MakeXYWH(rect.x(), rect.y(),
                                          rect.width(), rect.height());
   canvas->clipRect(layer_skrect);
+  canvas->scale(contents_scale, contents_scale);
   for (PicturePile::Pile::const_iterator i = pile_.begin();
        i != pile_.end(); ++i) {
     if (!(*i)->LayerRect().Intersects(rect))

cc/picture_pile_impl.h

@@ -26,7 +26,11 @@ public:
   // Raster a subrect of this PicturePileImpl into the given canvas.
   // It's only safe to call paint on a cloned version.
   // It is assumed that contentsScale has already been applied to this canvas.
-  void Raster(SkCanvas* canvas, gfx::Rect rect, RenderingStats* stats);
+  void Raster(
+      SkCanvas* canvas,
+      gfx::Rect rect,
+      float contents_scale,
+      RenderingStats* stats);
 
 private:
   friend class PicturePile;

cc/test/fake_picture_layer_tiling_client.cc

@@ -21,7 +21,8 @@ scoped_refptr<Tile> FakePictureLayerTilingClient::CreateTile(
                                      pile_.get(),
                                      tile_size_,
                                      GL_RGBA,
-                                     rect));
+                                     rect,
+                                     1));
 }
 
 void FakePictureLayerTilingClient::SetTileSize(gfx::Size tile_size) {

cc/tile.cc

@@ -13,12 +13,14 @@ Tile::Tile(TileManager* tile_manager,
            PicturePileImpl* picture_pile,
            gfx::Size tile_size,
            GLenum format,
-           gfx::Rect rect_inside_picture)
+           gfx::Rect rect_inside_picture,
+           float contents_scale)
   : tile_manager_(tile_manager),
     picture_pile_(picture_pile),
     tile_size_(tile_size),
     format_(format),
-    rect_inside_picture_(rect_inside_picture) {
+    rect_inside_picture_(rect_inside_picture),
+    contents_scale_(contents_scale) {
   tile_manager_->RegisterTile(this);
 }
 

cc/tile.h

@@ -26,7 +26,8 @@ class CC_EXPORT Tile : public base::RefCounted<Tile> {
        PicturePileImpl* picture_pile,
        gfx::Size tile_size,
        GLenum format,
-       gfx::Rect rect_inside_picture);
+       gfx::Rect rect_inside_picture,
+       float contents_scale);
 
   const PicturePileImpl* picture_pile() const {
     return picture_pile_.get();
@@ -59,6 +60,7 @@ class CC_EXPORT Tile : public base::RefCounted<Tile> {
   ManagedTileState& managed_state() { return managed_state_; }
   const ManagedTileState& managed_state() const { return managed_state_; }
   size_t bytes_consumed_if_allocated() const;
+  float contents_scale() const { return contents_scale_; }
 
   // Normal private methods.
   friend class base::RefCounted<Tile>;
@@ -69,6 +71,7 @@ class CC_EXPORT Tile : public base::RefCounted<Tile> {
   gfx::Rect tile_size_;
   GLenum format_;
   gfx::Rect rect_inside_picture_;
+  float contents_scale_;
   gfx::Rect opaque_rect_;
 
   TilePriority priority_[2];

cc/tile_manager.cc

@@ -23,6 +23,7 @@ namespace {
 void RasterizeTile(cc::PicturePileImpl* picture_pile,
                    uint8_t* mapped_buffer,
                    const gfx::Rect& rect,
+                   float contents_scale,
                    cc::RenderingStats* stats) {
   TRACE_EVENT0("cc", "RasterizeTile");
   DCHECK(mapped_buffer);
@@ -32,7 +33,11 @@ void RasterizeTile(cc::PicturePileImpl* picture_pile,
   bitmap.setPixels(mapped_buffer);
   SkDevice device(bitmap);
   SkCanvas canvas(&device);
-  picture_pile->Raster(&canvas, rect, stats);
+  picture_pile->Raster(
+      &canvas,
+      rect,
+      contents_scale,
+      stats);
 }
 
 const char* kRasterThreadNamePrefix = "CompositorRaster";
@@ -322,6 +327,7 @@ void TileManager::DispatchOneRasterTask(scoped_refptr<Tile> tile) {
                      resource_pool_->resource_provider()->mapPixelBuffer(
                          resource_id),
                      tile->rect_inside_picture_,
+                     tile->contents_scale(),
                      stats),
           base::Bind(&TileManager::OnRasterTaskCompleted,
                      base::Unretained(this),