Remove last isolate_dependnecy_* as found via gclient grep.

This is necessary before removing support for this once for all.

[email protected]
BUG=

Review URL: https://codereview.chromium.org/732773003

Cr-Commit-Position: refs/heads/master@{#304273}
diff --git a/gin/v8.isolate b/gin/v8.isolate
index 14d8a2c..a47dd9ea 100644
--- a/gin/v8.isolate
+++ b/gin/v8.isolate
@@ -5,7 +5,7 @@
   'conditions': [
     ['v8_use_external_startup_data==1', {
       'variables': {
-        'isolate_dependency_tracked': [
+        'files': [
           '<(PRODUCT_DIR)/natives_blob.bin',
           '<(PRODUCT_DIR)/snapshot_blob.bin',
         ],