Cross-process frames should be notified of device scale factor changes.

content/renderer/render_widget.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/render_widget.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/auto_reset.h"
@@ skipping 986 matching lines @@
 
   return size_;
 }
 
 void RenderWidget::Resize(const ResizeParams& params) {
   bool orientation_changed =
       screen_info_.orientationAngle != params.screen_info.orientationAngle ||
       screen_info_.orientationType != params.screen_info.orientationType;
 
   screen_info_ = params.screen_info;
-  SetDeviceScaleFactor(screen_info_.deviceScaleFactor);
+
+  if (device_scale_factor_ != screen_info_.deviceScaleFactor) {
+    device_scale_factor_ = screen_info_.deviceScaleFactor;
+    OnDeviceScaleFactorChanged();
+    ScheduleComposite();
+  }
 
   if (resizing_mode_selector_->NeverUsesSynchronousResize()) {
     // A resize ack shouldn't be requested if we have not ACK'd the previous
     // one.
     DCHECK(!params.needs_resize_ack || !next_paint_is_resize_ack());
   }
 
   // Ignore this during shutdown.
   if (!webwidget_)
     return;
@@ skipping 566 matching lines @@
   for (size_t i = 0u; i < text_input_info_history_.size() - 1u; ++i) {
     if (text_input_info_history_[i] != text_input_info_)
       return false;
   }
   return true;
 #else
   return !!webwidget_;
 #endif
 }
 
-void RenderWidget::SetDeviceScaleFactor(float device_scale_factor) {
+void RenderWidget::OnSetDeviceScaleFactor(float device_scale_factor) {
   if (device_scale_factor_ == device_scale_factor)
     return;
 
   device_scale_factor_ = device_scale_factor;
 
   OnDeviceScaleFactorChanged();
+  ScheduleComposite();
 
-  ScheduleComposite();
+  physical_backing_size_ = gfx::ScaleToCeiledSize(size_, device_scale_factor_);
 }
 
 bool RenderWidget::SetDeviceColorProfile(
     const std::vector<char>& color_profile) {
   if (device_color_profile_ == color_profile)
     return false;
 
   device_color_profile_ = color_profile;
 
   if (owner_delegate_)
@@ skipping 446 matching lines @@
 void RenderWidget::requestPointerUnlock() {
   mouse_lock_dispatcher_->UnlockMouse(webwidget_mouse_lock_target_.get());
 }
 
 bool RenderWidget::isPointerLocked() {
   return mouse_lock_dispatcher_->IsMouseLockedTo(
       webwidget_mouse_lock_target_.get());
 }
 
 }  // namespace content