Add flag for drawing layers to screen with Ganesh

cc/resources/picture_pile_impl.cc

Index: cc/resources/picture_pile_impl.cc
diff --git a/cc/resources/picture_pile_impl.cc b/cc/resources/picture_pile_impl.cc
index 8f2ef54e3f55738f12575ecc21c23e4f24309ab6..bfbec46a8edd9b823770adbcab9e48dbeb7f9ae9 100644
--- a/cc/resources/picture_pile_impl.cc
+++ b/cc/resources/picture_pile_impl.cc
@@ -79,10 +79,8 @@ void PicturePileImpl::Raster(
     gfx::Rect canvas_rect,
     float contents_scale,
     RasterStats* raster_stats) {
-
   DCHECK(contents_scale >= min_contents_scale_);
 
-  canvas->save();
   canvas->translate(-canvas_rect.x(), -canvas_rect.y());
 
   gfx::SizeF total_content_size = gfx::ScaleSize(tiling_.total_size(),
@@ -91,32 +89,12 @@ void PicturePileImpl::Raster(
   gfx::Rect content_rect = total_content_rect;
   content_rect.Intersect(canvas_rect);
 
-  // Clear one texel inside the right/bottom edge of the content rect,
-  // as it may only be partially covered by the picture playback.
-  // Also clear one texel outside the right/bottom edge of the content rect,
-  // as it may get blended in by linear filtering when zoomed in.
-  gfx::Rect deflated_content_rect = total_content_rect;
-  deflated_content_rect.Inset(0, 0, 1, 1);
-
-  gfx::Rect canvas_outside_content_rect = canvas_rect;
-  canvas_outside_content_rect.Subtract(deflated_content_rect);
-
-  if (!canvas_outside_content_rect.IsEmpty()) {
-    gfx::Rect inflated_content_rect = total_content_rect;
-    inflated_content_rect.Inset(0, 0, -1, -1);
-    canvas->clipRect(gfx::RectToSkRect(inflated_content_rect),
-                     SkRegion::kReplace_Op);
-    canvas->clipRect(gfx::RectToSkRect(deflated_content_rect),
-                     SkRegion::kDifference_Op);
-    canvas->drawColor(background_color_, SkXfermode::kSrc_Mode);
-  }
-
   // Rasterize the collection of relevant picture piles.
   gfx::Rect layer_rect = gfx::ToEnclosingRect(
       gfx::ScaleRect(content_rect, 1.f / contents_scale));
 
   canvas->clipRect(gfx::RectToSkRect(content_rect),
-                   SkRegion::kReplace_Op);
+                   SkRegion::kIntersect_Op);
   Region unclipped(content_rect);
 
   if (raster_stats) {
@@ -217,8 +195,57 @@ void PicturePileImpl::Raster(
 
   // We should always paint some part of |content_rect|.
   DCHECK(!unclipped.Contains(content_rect));
+}
+
+void PicturePileImpl::RasterToBitmap(
+    SkCanvas* canvas,
+    gfx::Rect canvas_rect,
+    float contents_scale,
+    RasterStats* raster_stats) {
+
+  canvas->save();
+  canvas->translate(-canvas_rect.x(), -canvas_rect.y());
+
+  gfx::SizeF total_content_size = gfx::ScaleSize(tiling_.total_size(),
+                                                 contents_scale);
+  gfx::Rect total_content_rect(gfx::ToCeiledSize(total_content_size));
+  gfx::Rect content_rect = total_content_rect;
+  content_rect.Intersect(canvas_rect);
+
+#ifndef NDEBUG
+  // Any non-painted areas will be left in this color.
+  canvas->clear(DebugColors::NonPaintedFillColor());
+#endif  // NDEBUG
+
+  // TODO(enne): this needs to be rolled together with the border clear

[enne (OOO), 2013/05/13 19:33:10]

It is definitely weird to clear to transparent and then clear some border pixels
to the background color in the same function.  vmpstr tried to change this to
just clearing to the background color and got reverted.  I've left these two
clears as written previously to avoid changing behavior, and will follow up to
try to combine them.

+  SkPaint paint;
+  paint.setAntiAlias(false);
+  paint.setXfermodeMode(SkXfermode::kClear_Mode);
+  canvas->drawRect(gfx::RectToSkRect(content_rect), paint);
+
+  // Clear one texel inside the right/bottom edge of the content rect,
+  // as it may only be partially covered by the picture playback.
+  // Also clear one texel outside the right/bottom edge of the content rect,
+  // as it may get blended in by linear filtering when zoomed in.
+  gfx::Rect deflated_content_rect = total_content_rect;
+  deflated_content_rect.Inset(0, 0, 1, 1);
+
+  gfx::Rect canvas_outside_content_rect = canvas_rect;
+  canvas_outside_content_rect.Subtract(deflated_content_rect);
+
+  if (!canvas_outside_content_rect.IsEmpty()) {
+    gfx::Rect inflated_content_rect = total_content_rect;
+    inflated_content_rect.Inset(0, 0, -1, -1);
+    canvas->clipRect(gfx::RectToSkRect(inflated_content_rect),
+                     SkRegion::kReplace_Op);
+    canvas->clipRect(gfx::RectToSkRect(deflated_content_rect),
+                     SkRegion::kDifference_Op);
+    canvas->drawColor(background_color_, SkXfermode::kSrc_Mode);
+  }
 
   canvas->restore();
+
+  Raster(canvas, canvas_rect, contents_scale, raster_stats);
 }
 
 skia::RefPtr<SkPicture> PicturePileImpl::GetFlattenedPicture() {