Check for already existing entry when adding to SiteProcessMap.

chrome/test/data/extensions/web_request_blocking/manifest.json

Index: chrome/test/data/extensions/web_request_blocking/manifest.json
diff --git a/chrome/test/data/extensions/web_request_blocking/manifest.json b/chrome/test/data/extensions/web_request_blocking/manifest.json
new file mode 100644
index 0000000000000000000000000000000000000000..f97bea388f3e428147f7fe5a7f10e53f9cabdaee
--- /dev/null
+++ b/chrome/test/data/extensions/web_request_blocking/manifest.json
@@ -0,0 +1,8 @@
+{
+  "name": "webRequest Blocking",
+  "version": "1.0",
+  "manifest_version": 2,
+  "description": "Tests navigation to a page blocked by webRequest API.",
+  "permissions": ["webRequest", "webRequestBlocking", "tabs", "<all_urls>"],

[Devlin, 2017/03/11 01:52:18]

is tabs needed?

[nasko, 2017/03/13 17:22:03]

Yes, it was used by tabs.create API call made in the test. I've removed it after
fixing the test.

[Devlin, 2017/03/13 19:19:56]

Fun fact: tabs.create doesn't require the tabs permission.

+  "web_accessible_resources": [ "blocked.html" ]
+}