DevTools: allow capturing screenshots from command menu.

third_party/WebKit/Source/devtools/front_end/emulation/DeviceModeModel.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.
 /**
  * @implements {SDK.TargetManager.Observer}
  * @unrestricted
  */
 Emulation.DeviceModeModel = class {
   /**
    * @param {function()} updateCallback
@@ skipping 618 matching lines @@
    */
   async captureScreenshot(fullSize) {
     var screenCaptureModel = this._target ? this._target.model(SDK.ScreenCaptureModel) : null;
     if (!screenCaptureModel)
       return null;
 
     var metrics = await screenCaptureModel.fetchLayoutMetrics();
     if (!metrics)
       return null;
 
+    if (!this._emulatedPageSize)
+      this._calculateAndEmulate(false);
+
     var pageSize = fullSize ? new UI.Size(metrics.contentWidth, metrics.contentHeight) : this._emulatedPageSize;
     var promises = [];
     promises.push(
         this._target.emulationAgent().setVisibleSize(Math.floor(pageSize.width), Math.floor(pageSize.height)));
     if (fullSize) {
       promises.push(this._target.emulationAgent().forceViewport(0, 0, 1));
     } else {
       promises.push(this._target.emulationAgent().forceViewport(
           Math.floor(metrics.viewportX), Math.floor(metrics.viewportY), metrics.viewportScale));
     }
     promises.push(this._target.emulationAgent().invoke_setDeviceMetricsOverride({
       width: 0,
       height: 0,
       deviceScaleFactor: this._appliedDeviceScaleFactor,
       mobile: this._isMobile(),
       fitWindow: false,
       scale: 1,
     }));
     await Promise.all(promises);
 
     var screenshot = await screenCaptureModel.captureScreenshot('png', 100);
+    this._calculateAndEmulate(false);

[dgozman, 2017/04/21 20:40:54]

You can move this back now.

[pfeldman, 2017/04/21 20:51:35]

Done.

     this._target.emulationAgent().setVisibleSize(
         Math.floor(this._emulatedPageSize.width * this._scale),
         Math.floor(this._emulatedPageSize.height * this._scale));
     this._target.emulationAgent().resetViewport();
-    this._calculateAndEmulate(false);
     return screenshot;
   }
 
   _deviceMetricsOverrideAppliedForTest() {
     // Used for sniffing in tests.
   }
 
   /**
    * @param {boolean} touchEnabled
    * @param {boolean} mobile
@@ skipping 20 matching lines @@
 
 Emulation.DeviceModeModel.MinDeviceSize = 50;
 Emulation.DeviceModeModel.MaxDeviceSize = 9999;
 
 
 Emulation.DeviceModeModel._defaultMobileUserAgent =
     'Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/%s Mobile Safari/537.36';
 Emulation.DeviceModeModel._defaultMobileUserAgent =
     SDK.MultitargetNetworkManager.patchUserAgentWithChromeVersion(Emulation.DeviceModeModel._defaultMobileUserAgent);
 Emulation.DeviceModeModel.defaultMobileScaleFactor = 2;