[DevTools] Implement screen size and position in Emulation.setDeviceMetricsOverrides.

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 "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 360 matching lines @@
     scale_ = params_.scale;
     offset_.SetPoint(params_.offset.x, params_.offset.y);
   }
 
   if (params_.screenPosition == WebDeviceEmulationParams::Desktop) {
     applied_widget_rect_.set_origin(original_view_screen_rect_.origin());
     widget_->screen_info_.rect = original_screen_info_.rect;
     widget_->screen_info_.availableRect = original_screen_info_.availableRect;
     widget_->window_screen_rect_ = original_window_screen_rect_;
   } else {
-    applied_widget_rect_.set_origin(gfx::Point(0, 0));
-    widget_->screen_info_.rect = applied_widget_rect_;
-    widget_->screen_info_.availableRect = applied_widget_rect_;
+    applied_widget_rect_.set_origin(params_.viewPosition);
+    gfx::Rect screen_rect = applied_widget_rect_;
+    if (!params_.screenSize.isEmpty()) {
+      screen_rect =
+          gfx::Rect(0, 0, params_.screenSize.width, params_.screenSize.height);
+    }
+    widget_->screen_info_.rect = screen_rect;
+    widget_->screen_info_.availableRect = screen_rect;
     widget_->window_screen_rect_ = applied_widget_rect_;
   }
 
   float applied_device_scale_factor = params_.deviceScaleFactor ?
       params_.deviceScaleFactor : original_screen_info_.deviceScaleFactor;
   widget_->screen_info_.deviceScaleFactor = applied_device_scale_factor;
 
   // Pass three emulation parameters to the blink side:
   // - we keep the real device scale factor in compositor to produce sharp image
   //   even when emulating different scale factor;
@@ skipping 2056 matching lines @@
 void RenderWidget::RegisterVideoHoleFrame(RenderFrameImpl* frame) {
   video_hole_frames_.AddObserver(frame);
 }
 
 void RenderWidget::UnregisterVideoHoleFrame(RenderFrameImpl* frame) {
   video_hole_frames_.RemoveObserver(frame);
 }
 #endif  // defined(VIDEO_HOLE)
 
 }  // namespace content