cc: Don't DCHECK for layers with non-invertible transforms.

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 538 matching lines @@
     if (tiling->contents_scale() < min_acceptable_scale)
       continue;
 
     for (PictureLayerTiling::CoverageIterator iter(tiling,
                                                    contents_scale_x(),
                                                    rect);
          iter;
          ++iter) {
       if (should_force_uploads && *iter)
         layer_tree_impl()->tile_manager()->ForceTileUploadToComplete(*iter);
+
+      bool tile_ready = false;
       // A null tile (i.e. no recording) is considered "ready".
-      if (!*iter || iter->drawing_info().IsReadyToDraw())
+      if (!*iter) {
+        tile_ready = true;
+      } else if (iter->drawing_info().IsReadyToDraw()) {
+        tile_ready = true;
+      } else if (!iter->priority(PENDING_TREE).is_live) {
+        NOTREACHED() << "All tiles considered for activation should be live";
+        tile_ready = true;
+      }
+      if (tile_ready)
         missing_region.Subtract(iter.geometry_rect());
     }
   }
 
   return missing_region.IsEmpty();
 }
 
 PictureLayerTiling* PictureLayerImpl::AddTiling(float contents_scale) {
   DCHECK(contents_scale >= MinimumContentsScale());
 
@@ skipping 307 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