[ChromeDriver] Fix screenshot size on Retina

Fix screenshot size on Retina screen by setting scale = 1 / device_pixel_ratio

Bug: chromedriver:752, chromedriver:2683
Change-Id: I1b378e2cda6f8b52f67337c754ae18cf2cb8130f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1772436Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: Tatiana Buldina <buldina@chromium.org>
Cr-Commit-Position: refs/heads/master@{#692284}

chrome/test/chromedriver/window_commands.cc

@@ -1719,12 +1719,33 @@ Status ExecuteScreenshot(Session* session,
   Status status = session->chrome->ActivateWebView(web_view->GetId());
   if (status.IsError())
     return status;
+  std::unique_ptr<base::Value> browser_info;
+  status = web_view->EvaluateScript(
+      std::string(),
+      "({x: document.documentElement.scrollLeft || document.body.scrollLeft,"
+      "  y: document.documentElement.scrollTop || document.body.scrollTop,"
+      "  height: window.innerHeight,"
+      "  width: window.innerWidth,"
+      "  device_pixel_ratio: window.devicePixelRatio})",
+      &browser_info);
+
+  std::unique_ptr<base::DictionaryValue> clip_dict =
+                                     std::make_unique<base::DictionaryValue>();
+  clip_dict->SetDouble("x", browser_info->FindKey("x")->GetDouble());
+  clip_dict->SetDouble("y", browser_info->FindKey("y")->GetDouble());
+  clip_dict->SetDouble("height", browser_info->FindKey("height")->GetDouble());
+  clip_dict->SetDouble("width", browser_info->FindKey("width")->GetDouble());
+  clip_dict->SetDouble(
+      "scale",
+      1 / browser_info->FindKey("device_pixel_ratio")->GetDouble());
+  base::DictionaryValue screenshot_params;
+  screenshot_params.SetDictionary("clip", std::move(clip_dict));
 
   std::string screenshot;
-  status = web_view->CaptureScreenshot(&screenshot, base::DictionaryValue());
+  status = web_view->CaptureScreenshot(&screenshot, screenshot_params);
   if (status.IsError()) {
     LOG(WARNING) << "screenshot failed, retrying";
-    status = web_view->CaptureScreenshot(&screenshot, base::DictionaryValue());
+    status = web_view->CaptureScreenshot(&screenshot, screenshot_params);
   }
   if (status.IsError())
     return status;