DevTools: allow capturing screenshots from command menu.

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

Index: third_party/WebKit/Source/devtools/front_end/emulation/DeviceModeModel.js
diff --git a/third_party/WebKit/Source/devtools/front_end/emulation/DeviceModeModel.js b/third_party/WebKit/Source/devtools/front_end/emulation/DeviceModeModel.js
index 8f3b0599ccc04f8fbacac2070d9b68372254b95f..061f5ca982dd61013556f590cdf1f6e51c72a074 100644
--- a/third_party/WebKit/Source/devtools/front_end/emulation/DeviceModeModel.js
+++ b/third_party/WebKit/Source/devtools/front_end/emulation/DeviceModeModel.js
@@ -636,6 +636,9 @@ Emulation.DeviceModeModel = class {
     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(
@@ -657,11 +660,11 @@ Emulation.DeviceModeModel = class {
     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;
   }