cc: Add tile-free software compositing mode.

cc/layers/picture_layer_impl.cc

 // Copyright 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.
 
 #include "cc/layers/picture_layer_impl.h"
 
 #include <algorithm>
 
 #include "base/time.h"
 #include "cc/base/math_util.h"
@@ skipping 139 matching lines @@
 
   // Keep track of the tilings that were used so that tilings that are
   // unused can be considered for removal.
   std::vector<PictureLayerTiling*> seen_tilings;
 
   for (PictureLayerTilingSet::CoverageIterator iter(
       tilings_.get(), contents_scale_x(), rect, ideal_contents_scale_);
        iter;
        ++iter) {
     gfx::Rect geometry_rect = iter.geometry_rect();
-    if (!*iter || !iter->drawing_info().IsReadyToDraw()) {
+    if (!*iter || (!iter->drawing_info().IsReadyToDraw() &&
+                   !append_quads_data->cannot_append_tile_draw_quads)) {
       if (DrawCheckerboardForMissingTiles()) {
         // TODO(enne): Figure out how to show debug "invalidated checker" color
         scoped_ptr<CheckerboardDrawQuad> quad = CheckerboardDrawQuad::Create();
         SkColor color = DebugColors::DefaultCheckerboardColor();
         quad->SetNew(shared_quad_state, geometry_rect, color);
         if (quad_sink->Append(quad.PassAs<DrawQuad>(), append_quads_data))
           append_quads_data->num_missing_tiles++;
       } else {
         SkColor color = background_color();
         // TODO(wangxianzhu): Change the next |if| condition once we support
@@ skipping 16 matching lines @@
         quad->SetNew(shared_quad_state, geometry_rect, color);
         if (quad_sink->Append(quad.PassAs<DrawQuad>(), append_quads_data))
           append_quads_data->num_missing_tiles++;
       }
 
       append_quads_data->had_incomplete_tile = true;
       continue;
     }
 
     const ManagedTileState::DrawingInfo& drawing_info = iter->drawing_info();
-    switch (drawing_info.mode()) {
+    ManagedTileState::DrawingInfo::Mode mode = iter->drawing_info().mode();
+    if (append_quads_data->cannot_append_tile_draw_quads &&

[enne (OOO), 2013/04/28 22:42:27]

I think you should not append one picture quad per tile, and maybe just pull all
this up to the top and append one picture quad for the whole layer like this
does:
https://codereview.chromium.org/13863015/diff/4001/cc/layers/picture_layer_im...

[aelias_OOO_until_Jul13, 2013/04/30 07:28:20]

Agreed, although cut-and-pasting that snippet results in broken rendering for
me.  Did you change the meaning of one of the rects as part of that patch?

+        mode == ManagedTileState::DrawingInfo::RESOURCE_MODE)
+      mode = ManagedTileState::DrawingInfo::PICTURE_PILE_MODE;
+    switch (mode) {
       case ManagedTileState::DrawingInfo::RESOURCE_MODE: {
         gfx::RectF texture_rect = iter.texture_rect();
         gfx::Rect opaque_rect = iter->opaque_rect();
         opaque_rect.Intersect(content_rect);
 
         if (iter->contents_scale() != ideal_contents_scale_)
           append_quads_data->had_incomplete_tile = true;
 
         scoped_ptr<TileDrawQuad> quad = TileDrawQuad::Create();
         quad->SetNew(shared_quad_state,
@@ skipping 332 matching lines @@
       return 0;
     return iter->drawing_info().get_resource_id();
   }
   return 0;
 }
 
 bool PictureLayerImpl::AreVisibleResourcesReady() const {
   DCHECK(layer_tree_impl()->IsPendingTree());
   DCHECK(ideal_contents_scale_);
 
+  if (layer_tree_impl()->settings().tile_free_software_compositing)

[enne (OOO), 2013/04/28 22:42:27]

Settings are considered to be immutable.  I'm not sure how you can have a hybrid
hardware/software layer tree if you have this setting turned on, since this
conditional is undesirable for normal operation.

To be honest, I'm confused how activation enters into consideration for the
capture picture mode.

[aelias_OOO_until_Jul13, 2013/04/30 07:28:20]

I deleted this, it was a workaround for the issue fixed by
https://codereview.chromium.org/14061028/

+    return true;
+
   if (!tilings_->num_tilings())
     return true;
 
   gfx::Rect rect(visible_content_rect());
 
   float min_acceptable_scale =
       std::min(raster_contents_scale_, ideal_contents_scale_);
 
   TreePriority tree_priority =
       layer_tree_impl()->tile_manager()->GlobalState().tree_priority;
@@ skipping 356 matching lines @@
 scoped_ptr<base::Value> PictureLayerImpl::AsValue() const {
   scoped_ptr<base::DictionaryValue> state(new base::DictionaryValue());
   LayerImpl::AsValueInto(state.get());
 
   state->SetDouble("ideal_contents_scale", ideal_contents_scale_);
   state->Set("tilings", tilings_->AsValue().release());
   return state.PassAs<base::Value>();
 }
 
 }  // namespace cc