[DevTools] Separate ScreenCaptureModel out of ResourceTreeModel.

third_party/WebKit/Source/devtools/front_end/emulation/DeviceModeView.js

 // 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.
 /**
  * @unrestricted
  */
 Emulation.DeviceModeView = class extends UI.VBox {
   constructor() {
     super(true);
     this.setMinimumSize(150, 150);
@@ skipping 342 matching lines @@
   }
 
   /**
    * @override
    */
   willHide() {
     this._model.emulate(Emulation.DeviceModeModel.Type.None, null, null);
   }
 
   captureScreenshot() {
-    var mainTarget = SDK.targetManager.mainTarget();
-    if (!mainTarget)
+    var target = this._model.target();
+    if (!target)
+      return;
+    var screenCaptureModel = target.model(SDK.ScreenCaptureModel);
+    if (!screenCaptureModel)
       return;
     SDK.DOMModel.muteHighlight();
 
     var zoomFactor = UI.zoomManager.zoomFactor();
     var rect = this._contentArea.getBoundingClientRect();
     var availableSize = new UI.Size(Math.max(rect.width * zoomFactor, 1), Math.max(rect.height * zoomFactor, 1));
     var outlineVisible = this._model.deviceOutlineSetting().get();
 
     if (availableSize.width < this._model.screenRect().width ||
         availableSize.height < this._model.screenRect().height) {
       UI.inspectorView.minimize();
       this._model.deviceOutlineSetting().set(false);
     }
 
-    mainTarget.pageAgent().captureScreenshot('png', 100, screenshotCaptured.bind(this));
+    screenCaptureModel.captureScreenshot('png', 100).then(screenshotCaptured.bind(this));
 
     /**
-     * @param {?Protocol.Error} error
-     * @param {string} content
+     * @param {?string} content
      * @this {Emulation.DeviceModeView}
      */
-    function screenshotCaptured(error, content) {
+    function screenshotCaptured(content) {
       this._model.deviceOutlineSetting().set(outlineVisible);
       var dpr = window.devicePixelRatio;
       var outlineRect = this._model.outlineRect().scale(dpr);
       var screenRect = this._model.screenRect().scale(dpr);
       screenRect.left -= outlineRect.left;
       screenRect.top -= outlineRect.top;
       var visiblePageRect = this._model.visiblePageRect().scale(dpr);
       visiblePageRect.left += screenRect.left;
       visiblePageRect.top += screenRect.top;
       outlineRect.left = 0;
       outlineRect.top = 0;
 
       SDK.DOMModel.unmuteHighlight();
       UI.inspectorView.restore();
 
-      if (error) {
-        console.error(error);
+      if (content === null)
         return;
-      }
 
       // Create a canvas to splice the images together.
       var canvas = createElement('canvas');
       var ctx = canvas.getContext('2d');
       canvas.width = outlineRect.width;
       canvas.height = outlineRect.height;
       ctx.imageSmoothingEnabled = false;
 
       var promise = Promise.resolve();
       if (this._model.outlineImage())
@@ skipping 34 matching lines @@
       /**
        * @this {Emulation.DeviceModeView}
        */
       function paintScreenshot() {
         var pageImage = new Image();
         pageImage.src = 'data:image/png;base64,' + content;
         pageImage.onload = () => {
           ctx.drawImage(
               pageImage, visiblePageRect.left, visiblePageRect.top, Math.min(pageImage.naturalWidth, screenRect.width),
               Math.min(pageImage.naturalHeight, screenRect.height));
-          var url = mainTarget && mainTarget.inspectedURL();
+          var url = target.inspectedURL();
           var fileName = url ? url.trimURL().removeURLFragment() : '';
           if (this._model.type() === Emulation.DeviceModeModel.Type.Device)
             fileName += Common.UIString('(%s)', this._model.device().title);
           // Trigger download.
           var link = createElement('a');
           link.download = fileName + '.png';
           link.href = canvas.toDataURL('image/png');
           link.click();
         };
       }
@@ skipping 94 matching lines @@
     return Promise.resolve();
   }
 
   /**
    * @param {number} size
    */
   _onMarkerClick(size) {
     this._applyCallback.call(null, size);
   }
 };