Update viewport_to_dip_scale on bound compositor host

content/renderer/pepper/pepper_plugin_instance_impl.cc

 // Copyright (c) 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 "content/renderer/pepper/pepper_plugin_instance_impl.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bit_cast.h"
@@ skipping 2331 matching lines @@
     }
   }
 
   EnterResourceNoLock<PPB_Graphics3D_API> enter_3d(device, false);
   PPB_Graphics3D_Impl* graphics_3d =
       enter_3d.succeeded()
           ? static_cast<PPB_Graphics3D_Impl*>(enter_3d.object())
           : NULL;
 
   if (compositor) {
     if (compositor->BindToInstance(this)) {

[oshima, 2016/08/23 22:25:49]

+bbudge@ (owner)

I feel it's better to do this in BindToInstance, but I'd follow the owner's
recommendation.

[bbudge, 2016/08/23 23:32:39]

I might not understand the comment, but this seems like the only way, since the
compositor might not have a viewport_to_dip_scale_ value set. Also, this class
makes another call to set_viewport_to_dip_scale when handling view changes:

https://cs.chromium.org/chromium/src/content/renderer/pepper/pepper_plugin_in...

       bound_compositor_ = compositor;
+      bound_compositor_->set_viewport_to_dip_scale(viewport_to_dip_scale_);
       UpdateLayer(true);
       return PP_TRUE;
     }
   } else if (graphics_2d) {
     if (graphics_2d->BindToInstance(this)) {
       bound_graphics_2d_platform_ = graphics_2d;
+      bound_graphics_2d_platform_->set_viewport_to_dip_scale(
+          viewport_to_dip_scale_);
       UpdateLayer(true);
       return PP_TRUE;
     }
   } else if (graphics_3d) {
     // Make sure graphics can only be bound to the instance it is
     // associated with.
     if (graphics_3d->pp_instance() == pp_instance() &&
         graphics_3d->BindToInstance(true)) {
       bound_graphics_3d_ = graphics_3d;
       UpdateLayer(true);
@@ skipping 1072 matching lines @@
     const cc::TextureMailbox& mailbox) const {
   auto it =
       std::find_if(texture_ref_counts_.begin(), texture_ref_counts_.end(),
                    [&mailbox](const TextureMailboxRefCount& ref_count) {
                      return ref_count.first.mailbox() == mailbox.mailbox();
                    });
   return it != texture_ref_counts_.end();
 }
 
 }  // namespace content