Re-land: exo: Take blending into account when setting opaque property.

components/exo/surface.cc

 // Copyright 2015 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 "components/exo/surface.h"
 
 #include <utility>
 
 #include "base/callback_helpers.h"
 #include "base/logging.h"
@@ skipping 459 matching lines @@
   if (old_surface_id != surface_id_) {
     float contents_surface_to_layer_scale = 1.0;
     window_->layer()->SetShowSurface(
         surface_id_,
         base::Bind(&SatisfyCallback, base::Unretained(surface_manager_)),
         base::Bind(&RequireCallback, base::Unretained(surface_manager_)),
         content_size_, contents_surface_to_layer_scale, content_size_);
     window_->layer()->SetBounds(
         gfx::Rect(window_->layer()->bounds().origin(), content_size_));
     window_->layer()->SetFillsBoundsOpaquely(
-        state_.alpha == 1.0f &&

[jbauman, 2016/06/27 20:51:41]

So if the blend mode is SkXfermode::kSrc_Mode then the alpha should be ignored?
And the opaque_region should always be empty if alpha is not 1.0?

[reveman, 2016/06/27 20:54:21]

We should probably define this as part of the alpha blending interface we added.
For now we can say that if the client sets alpha to less than 1 and opaque to
true then output is undefined.

-
+        state_.blend_mode == SkXfermode::kSrc_Mode ||
         state_.opaque_region.contains(
             gfx::RectToSkIRect(gfx::Rect(content_size_))));
   }
 
   // Reset damage.
   pending_damage_.setEmpty();
 
   DCHECK(!current_resource_.id ||
          factory_owner_->release_callbacks_.count(current_resource_.id));
 
@@ skipping 335 matching lines @@
 
 int64_t Surface::GetPropertyInternal(const void* key,
                                      int64_t default_value) const {
   std::map<const void*, Value>::const_iterator iter = prop_map_.find(key);
   if (iter == prop_map_.end())
     return default_value;
   return iter->second.value;
 }
 
 }  // namespace exo