DevTools: add "npm test" to run tests by fetching content shells

third_party/WebKit/Source/devtools/scripts/js_build/gulpfile.js

Index: third_party/WebKit/Source/devtools/scripts/js_build/gulpfile.js
diff --git a/third_party/WebKit/Source/devtools/scripts/js_build/gulpfile.js b/third_party/WebKit/Source/devtools/scripts/js_build/gulpfile.js
index 43c95b34598765a1e1ec557ba23bfa38a5bf18f4..22a3af2c6d8b454d138d03f93e87cd617ba4d606 100644
--- a/third_party/WebKit/Source/devtools/scripts/js_build/gulpfile.js
+++ b/third_party/WebKit/Source/devtools/scripts/js_build/gulpfile.js
@@ -14,6 +14,9 @@ var gulp = require("gulp");
 var concatenateProtocols = require("./ConcatenateProtocols.js");
 var utils = require("../utils.js");
 
+var chromiumGitRef = process.env.CHROMIUM_COMMIT || "master";
+var v8GitRef = process.env.V8_COMMIT || "master";
+
 var devtoolsPath = path.resolve(path.join(__dirname, "../.."));
 var frontendPath = path.join(devtoolsPath, "front_end");
 var releasePath = path.join(devtoolsPath, "release");
@@ -77,14 +80,13 @@ function concatenateProtocolTask()
 gulp.task("fetchProtocol", ["clean"], fetchProtocolTask);
 function fetchProtocolTask(done)
 {
-    var browserProtocolURL = "https://chromium.googlesource.com/chromium/src/+/master/third_party/WebKit/Source/core/inspector/browser_protocol.json?format=TEXT";
+    var browserProtocolURL = `https://chromium.googlesource.com/chromium/src/+/${chromiumGitRef}/third_party/WebKit/Source/core/inspector/browser_protocol.json?format=TEXT`;
     var browserProtocolFile = path.join(releasePath, "browser_protocol.json");
     var browserProtocolPromise = fetchAndSaveCodePromise(browserProtocolURL, browserProtocolFile);
 
-    var jsProtocolURL = "https://chromium.googlesource.com/v8/v8/+/master/src/inspector/js_protocol.json?format=TEXT";
+    var jsProtocolURL = `https://chromium.googlesource.com/v8/v8/+/${v8GitRef}/src/inspector/js_protocol.json?format=TEXT`;
     var jsProtocolFile = path.join(releasePath, "js_protocol.json");
     var jsProtocolPromise = fetchAndSaveCodePromise(jsProtocolURL, jsProtocolFile);
-
     Promise.all([browserProtocolPromise, jsProtocolPromise])
         .then(() => done())
         .catch(err => console.log("Error fetching protocols:", err));
@@ -104,7 +106,7 @@ function generateSupportedCSSProperties()
 gulp.task("fetchSupportedCSSProperties", ["clean"], fetchSupportedCSSProperties);
 function fetchSupportedCSSProperties(done)
 {
-    var supportedCSSPropertiesURL = "https://chromium.googlesource.com/chromium/src/+/master/third_party/WebKit/Source/core/css/CSSProperties.in?format=TEXT";
+    var supportedCSSPropertiesURL = `https://chromium.googlesource.com/chromium/src/+/${chromiumGitRef}/third_party/WebKit/Source/core/css/CSSProperties.in?format=TEXT`;
     var supportedCSSPropertiesFile = path.join(releasePath, "CSSProperties.in");
     fetchAndSaveCodePromise(supportedCSSPropertiesURL, supportedCSSPropertiesFile)
         .then(() => done())