Make layout test harness extensible with custom layout tests directory

third_party/WebKit/Source/devtools/scripts/npm_test.js

Index: third_party/WebKit/Source/devtools/scripts/npm_test.js
diff --git a/third_party/WebKit/Source/devtools/scripts/npm_test.js b/third_party/WebKit/Source/devtools/scripts/npm_test.js
index dc14020ce579554163b4242a725751546e6e976d..e7c6e57e5c6f9a1c0d0284a0d048edb5dfa0d00b 100644
--- a/third_party/WebKit/Source/devtools/scripts/npm_test.js
+++ b/third_party/WebKit/Source/devtools/scripts/npm_test.js
@@ -24,8 +24,9 @@ var MAX_CONTENT_SHELLS = 10;
 var PLATFORM = getPlatform();
 var PYTHON = process.platform === "win32" ? "python.bat" : "python";
 
-var BLINK_TEST_PATH = path.resolve(__dirname, "..", "..", "..", "..", "..", "blink", "tools", "run_layout_tests.py");
+var TEST_SCRIPT_PATH = path.resolve(__dirname, "..", "..", "..", "Tools", "Scripts", "run-inspector-tests");
 var CACHE_PATH = path.resolve(__dirname, "..", ".test_cache");
+var TEST_PATH = path.resolve(__dirname, "..", "layout_tests");
 var SOURCE_PATH = path.resolve(__dirname, "..", "front_end");
 
 function main(){
@@ -225,6 +226,7 @@ function build(contentShellResourcesPath)
 function runTests(buildDirectoryPath)
 {
     var testArgs = [
+        `--layout-tests-directory=${TEST_PATH}`,
         "--additional-drt-flag=--debug-devtools",
         "--no-pixel-tests",
         "--build-directory",
@@ -238,7 +240,7 @@ function runTests(buildDirectoryPath)
         console.log("Click on link and in console execute: test()");
         console.log("=============================================\n");
     }
-    var args = [BLINK_TEST_PATH].concat(testArgs).concat(getTestFlags());
+    var args = [TEST_SCRIPT_PATH].concat(testArgs).concat(getTestFlags());
     console.log(`Running layout tests with args: ${args}`);
     childProcess.spawn(PYTHON, args, {stdio: "inherit"});
 }
@@ -256,8 +258,5 @@ function getInspectorTests()
     var specificTests = process.argv.filter(arg => utils.includes(arg, "inspector"));
     if (specificTests.length)
         return specificTests;
-    return [
-        "inspector*",
-        "http/tests/inspector*",
-    ];
-}
+    return [];
+}