[DevTools] Handle emulated device scale factor and original device scale factor properly.

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 <utility>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
@@ skipping 570 matching lines @@
     resize_params.physical_backing_size = physical_backing_size_;
     resize_params.visible_viewport_size = visible_viewport_size_;
     resize_params.top_controls_shrink_blink_size =
         top_controls_shrink_blink_size_;
     resize_params.top_controls_height = top_controls_height_;
     resize_params.resizer_rect = resizer_rect_;
     resize_params.is_fullscreen_granted = is_fullscreen_granted_;
     resize_params.display_mode = display_mode_;
     screen_metrics_emulator_.reset(new RenderWidgetScreenMetricsEmulator(
         this, params, resize_params, view_screen_rect_, window_screen_rect_));
+    screen_metrics_emulator_->Apply();

[dgozman, 2016/03/02 01:19:56]

Similarly, you'll have to decouple Apply from ChangeEmulationParams as well.

[oshima, 2016/03/02 03:15:07]

The instance is already set so it's not necessary. I'm happy to change if you
think that's better. Please let me know. 

   } else {
     screen_metrics_emulator_->ChangeEmulationParams(params);
   }
 }
 
 void RenderWidget::OnDisableDeviceEmulation() {
   screen_metrics_emulator_.reset();
 }
 
 void RenderWidget::OnColorProfile(const std::vector<char>& color_profile) {
@@ skipping 491 matching lines @@
   // NOTE: We may have entered fullscreen mode without changing our size.
   bool fullscreen_change =
       is_fullscreen_granted_ != params.is_fullscreen_granted;
   is_fullscreen_granted_ = params.is_fullscreen_granted;
   display_mode_ = params.display_mode;
 
   webwidget_->setTopControlsHeight(params.top_controls_height,
                                    top_controls_shrink_blink_size_);
 
   if (resized) {
-    gfx::Size new_widget_size =
-        IsUseZoomForDSFEnabled() ? physical_backing_size_ : size_;
+    gfx::Size new_widget_size = size_;
+    if (IsUseZoomForDSFEnabled()) {
+      new_widget_size = gfx::ScaleToCeiledSize(new_widget_size,
+                                               GetOriginalDeviceScaleFactor());
+    }
     // When resizing, we want to wait to paint before ACK'ing the resize.  This
     // ensures that we only resize as fast as we can paint.  We only need to
     // send an ACK if we are resized to a non-empty rect.
     webwidget_->resize(new_widget_size);
   }
   WebSize visual_viewport_size;
 
   if (IsUseZoomForDSFEnabled()) {
-    visual_viewport_size = gfx::ScaleToCeiledSize(params.visible_viewport_size,
-                                                  device_scale_factor_);
+    visual_viewport_size = gfx::ScaleToCeiledSize(
+        params.visible_viewport_size,
+        GetOriginalDeviceScaleFactor());
   } else {
     visual_viewport_size = visible_viewport_size_;
   }
 
   webwidget()->resizeVisualViewport(visual_viewport_size);
 
   if (params.new_size.IsEmpty() || params.physical_backing_size.IsEmpty()) {
     // In this case there is no paint/composite and therefore no
     // ViewHostMsg_UpdateRect to send the resize ack with. We'd need to send the
     // ack through a fake ViewHostMsg_UpdateRect or a different message.
@@ skipping 346 matching lines @@
     webwidget_->confirmComposition(WebWidget::KeepSelection);
   else
     webwidget_->confirmComposition(WebWidget::DoNotKeepSelection);
   input_handler_->set_handling_input_event(false);
   UpdateCompositionInfo(true);
 }
 
 void RenderWidget::OnDeviceScaleFactorChanged() {
   if (!compositor_)
     return;
-
   if (IsUseZoomForDSFEnabled())
-    compositor_->SetPaintedDeviceScaleFactor(device_scale_factor_);
+    compositor_->SetPaintedDeviceScaleFactor(GetOriginalDeviceScaleFactor());
   else
     compositor_->setDeviceScaleFactor(device_scale_factor_);
 }
 
 void RenderWidget::OnRepaint(gfx::Size size_to_paint) {
   // During shutdown we can just ignore this message.
   if (!webwidget_)
     return;
 
   // Even if the browser provides an empty damage rect, it's still expecting to
@@ skipping 70 matching lines @@
     return;
   composition_character_bounds_ = character_bounds;
   composition_range_ = range;
   Send(new InputHostMsg_ImeCompositionRangeChanged(
       routing_id(), composition_range_, composition_character_bounds_));
 #endif
 }
 
 void RenderWidget::convertViewportToWindow(blink::WebRect* rect) {
   if (IsUseZoomForDSFEnabled()) {
-    float reverse = 1 / device_scale_factor_;
+    float reverse = 1 / GetOriginalDeviceScaleFactor();
     // TODO(oshima): We may need to allow pixel precision here as the the
     // anchor element can be placed at half pixel.
     gfx::Rect window_rect =
         gfx::ScaleToEnclosedRect(gfx::Rect(*rect), reverse);
     rect->x = window_rect.x();
     rect->y = window_rect.y();
     rect->width = window_rect.width();
     rect->height = window_rect.height();
   }
 }
 
 void RenderWidget::convertWindowToViewport(blink::WebFloatRect* rect) {
   if (IsUseZoomForDSFEnabled()) {
-    rect->x *= device_scale_factor_;
-    rect->y *= device_scale_factor_;
-    rect->width *= device_scale_factor_;
-    rect->height *= device_scale_factor_;
+    rect->x *= GetOriginalDeviceScaleFactor();
+    rect->y *= GetOriginalDeviceScaleFactor();
+    rect->width *= GetOriginalDeviceScaleFactor();
+    rect->height *= GetOriginalDeviceScaleFactor();
   }
 }
 
 void RenderWidget::OnShowImeIfNeeded() {
 #if defined(OS_ANDROID) || defined(USE_AURA)
   UpdateTextInputState(ShowIme::IF_NEEDED, ChangeSource::FROM_NON_IME);
 #endif
 
 // TODO(rouslan): Fix ChromeOS and Windows 8 behavior of autofill popup with
 // virtual keyboard.
@@ skipping 510 matching lines @@
 void RenderWidget::UnregisterVideoHoleFrame(RenderFrameImpl* frame) {
   video_hole_frames_.RemoveObserver(frame);
 }
 #endif  // defined(VIDEO_HOLE)
 
 void RenderWidget::OnWaitNextFrameForTests(int routing_id) {
   QueueMessage(new ViewHostMsg_WaitForNextFrameForTests_ACK(routing_id),
                MESSAGE_DELIVERY_POLICY_WITH_VISUAL_STATE);
 }
 
+float RenderWidget::GetOriginalDeviceScaleFactor() const {
+  return
+      screen_metrics_emulator_ ?
+      screen_metrics_emulator_->original_screen_info().deviceScaleFactor :
+      device_scale_factor_;
+}
+
 }  // namespace content