Update gdb_chrome.py for the new location of blink's gdb helper

Bug: 829697
Change-Id: Id67192084d36f8a730d05c9e0213893c7776ae6f
Reviewed-on: https://chromium-review.googlesource.com/1026194Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553198}

tools/gdb/gdb_chrome.py

@@ -30,9 +30,9 @@ import sys
 
 sys.path.insert(0, os.path.join(
     os.path.dirname(os.path.abspath(__file__)),
-    '..', '..', 'third_party', 'WebKit', 'Tools', 'gdb'))
+    '..', '..', 'third_party', 'blink', 'tools', 'gdb'))
 try:
-  import webkit
+  import blink
 finally:
   sys.path.pop(0)