cc: Fix impl-side painting rasterization at >1 contents scales

Previously there was a content space vs. layer space mixup.  cc::Tile had a
member variable that was labeled rect_in_layer_space, but the tilings were
making a content space rect.  It's actually impossible to have an int rect in
layer space for most content spaces, so this got renamed to just be
content_space rect.

The actual bug was that this rect was being used to check if a given picture's
layer rect intersected it, so as soon as you got over bounds() / content_scale
away from the origin, the tile was getting nothing rastered to it and whatever
memory was in the canvas was being used, which happened to be old tiles.

R=aelias@chromium.org
BUG=164750


Review URL: https://chromiumcodereview.appspot.com/11466032

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@171964 0039d316-1c4b-4281-b951-d872f2087c98

cc/picture.cc

@@ -62,8 +62,8 @@ void Picture::Record(ContentLayerClient* painter,
                                          layer_rect_.y(),
                                          layer_rect_.width(),
                                          layer_rect_.height());
-  canvas->drawRect(layer_skrect, paint);
   canvas->clipRect(layer_skrect);
+  canvas->drawRect(layer_skrect, paint);
 
   gfx::RectF opaque_layer_rect;
   base::TimeTicks beginPaintTime = base::TimeTicks::Now();

cc/picture_pile_impl.cc

@@ -7,6 +7,7 @@
 #include "cc/rendering_stats.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkSize.h"
+#include "ui/gfx/rect_conversions.h"
 
 namespace cc {
 
@@ -45,21 +46,27 @@ scoped_refptr<PicturePileImpl> PicturePileImpl::CloneForDrawing() const {
 
 void PicturePileImpl::Raster(
     SkCanvas* canvas,
-    gfx::Rect rect,
+    gfx::Rect content_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
   canvas->save();
-  canvas->translate(-rect.x(), -rect.y());
-  SkRect layer_skrect = SkRect::MakeXYWH(rect.x(), rect.y(),
-                                         rect.width(), rect.height());
+  canvas->translate(-content_rect.x(), -content_rect.y());
+  SkRect layer_skrect = SkRect::MakeXYWH(
+      content_rect.x(),
+      content_rect.y(),
+      content_rect.width(),
+      content_rect.height());
   canvas->clipRect(layer_skrect);
   canvas->scale(contents_scale, contents_scale);
+
+  gfx::Rect layer_rect = gfx::ToEnclosedRect(gfx::ScaleRect(gfx::RectF(content_rect), 1 / contents_scale));
+
   for (PicturePile::Pile::const_iterator i = pile_.begin();
        i != pile_.end(); ++i) {
-    if (!(*i)->LayerRect().Intersects(rect))
+    if (!(*i)->LayerRect().Intersects(layer_rect))
       continue;
     (*i)->Raster(canvas);
 

cc/picture_pile_impl.h

@@ -34,7 +34,7 @@ public:
   // It is assumed that contentsScale has already been applied to this canvas.
   void Raster(
       SkCanvas* canvas,
-      gfx::Rect rect,
+      gfx::Rect content_rect,
       float contents_scale,
       RenderingStats* stats);
 

cc/tile.cc

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

cc/tile.h

@@ -26,7 +26,7 @@ class CC_EXPORT Tile : public base::RefCounted<Tile> {
        PicturePileImpl* picture_pile,
        gfx::Size tile_size,
        GLenum format,
-       gfx::Rect rect_inside_picture,
+       gfx::Rect content_rect,
        float contents_scale);
 
   PicturePileImpl* picture_pile() {
@@ -68,7 +68,7 @@ class CC_EXPORT Tile : public base::RefCounted<Tile> {
   scoped_refptr<PicturePileImpl> picture_pile_;
   gfx::Rect tile_size_;
   GLenum format_;
-  gfx::Rect rect_inside_picture_;
+  gfx::Rect content_rect_;
   float contents_scale_;
   gfx::Rect opaque_rect_;
 

cc/tile_manager.cc

@@ -413,7 +413,7 @@ void TileManager::DispatchOneRasterTask(
       FROM_HERE,
       picture_pile_clone.get(),
       resource_pool_->resource_provider()->mapPixelBuffer(resource_id),
-      tile->rect_inside_picture_,
+      tile->content_rect_,
       tile->contents_scale(),
       stats,
       base::Bind(&TileManager::OnRasterTaskCompleted,