DevTools: Support CHROMIUM_PATH on Windows

The launch_chrome.js npm script doesn't currently support the CHROMIUM_PATH variable like it does on other platforms.

This change simply copies the same logic from Linux/Mac.

Change-Id: Ic2a340f47b1dc87f9c7eefcdcf4de5ed39638c6e
Reviewed-on: https://chromium-review.googlesource.com/c/1481116
Reviewed-by: Dmitry Gozman <[email protected]>
Commit-Queue: Jeff Fisher <[email protected]>
Cr-Original-Commit-Position: refs/heads/master@{#634800}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 363f1d8ba93a40c9bbebb277e7be807e4e6fffc0
diff --git a/scripts/chrome_debug_launcher/launch_chrome.js b/scripts/chrome_debug_launcher/launch_chrome.js
index e7b2625..7c568a3 100644
--- a/scripts/chrome_debug_launcher/launch_chrome.js
+++ b/scripts/chrome_debug_launcher/launch_chrome.js
@@ -48,15 +48,19 @@
 
 function launchChromeWindows() {
   var chromeCanaryPath;
-  var suffix = '\\Google\\Chrome SxS\\Application\\chrome.exe';
-  var prefixes = [process.env.LOCALAPPDATA, process.env.PROGRAMFILES, process.env['PROGRAMFILES(X86)']];
-  for (var i = 0; i < prefixes.length; i++) {
-    var prefix = prefixes[i];
-    try {
-      chromeCanaryPath = path.join(prefix, suffix);
-      fs.accessSync(chromeCanaryPath);
-      break;
-    } catch (e) {
+  if (utils.isFile(process.env.CHROMIUM_PATH)) {
+    chromeCanaryPath = process.env.CHROMIUM_PATH;
+  } else {
+    var suffix = '\\Google\\Chrome SxS\\Application\\chrome.exe';
+    var prefixes = [process.env.LOCALAPPDATA, process.env.PROGRAMFILES, process.env['PROGRAMFILES(X86)']];
+    for (var i = 0; i < prefixes.length; i++) {
+      var prefix = prefixes[i];
+      try {
+        chromeCanaryPath = path.join(prefix, suffix);
+        fs.accessSync(chromeCanaryPath);
+        break;
+      } catch (e) {
+      }
     }
   }
   launchChrome(chromeCanaryPath, chromeArgs);