Convert Site Isolation Win bot to --isolate-extensions [2nd attempt].

chrome/test/BUILD.gn

Index: chrome/test/BUILD.gn
diff --git a/chrome/test/BUILD.gn b/chrome/test/BUILD.gn
index a6104a281c8e733ff84dc4071e4631c9b2c952c2..c5e2de187794874da07fa00b00b44e006c10d52e 100644
--- a/chrome/test/BUILD.gn
+++ b/chrome/test/BUILD.gn
@@ -1159,9 +1159,6 @@ if (!is_android) {
 
   group("mash_browser_tests") {
     testonly = true
-    data = [
-      "//testing/buildbot/filters/mojo.fyi.browser_tests.filter",
-    ]
     data_deps = [
       ":browser_tests",
     ]
@@ -1277,6 +1274,27 @@ test("browser_tests") {
     }
   }
 
+  # Adding all //testing/buildbot/filters/*.browser_tests.*filter files
+  # as a dependency.

[brettw, 2016/11/04 22:13:09]

Can you mention here what these files are used for? I wasn't aware of them
before this.

[Łukasz Anforowicz, 2016/11/04 23:27:59]

I am adding a //testing/buildbot/filters/README.md in
https://codereview.chromium.org/2472153002 - this is probably better than adding
a one-off comment here, right?

+  #
+  # They might not be used on all platforms (e.g. there is no mac bot coverage
+  # for --site-per-process today), but for simplicity we just include all of
+  # them below (doing this should help avoid unpleasant surprises when a bot
+  # config is switched in testing/buildbot/chromium.fyi.json without
+  # corresponding dependency changes here - see https://crbug.com/661447).
+  #
+  # To refresh, run the following command in bash:
+  # $ for i in $( \
+  #     find testing/buildbot/filters/ -name '*.browser_tests.*filter'); \
+  #   do echo "    \"//$i\","; done | sort
+  data += [
+    "//testing/buildbot/filters/browser-side-navigation.linux.browser_tests.filter",
+    "//testing/buildbot/filters/isolate-extensions.browser_tests.filter",
+    "//testing/buildbot/filters/mash.browser_tests.filter",
+    "//testing/buildbot/filters/mojo.fyi.browser_tests.filter",
+    "//testing/buildbot/filters/site-per-process.browser_tests.filter",
+  ]
+
   # TODO(jbudorick): In progress. See crbug.com/611756
   if (is_android) {
     deps += [
@@ -2008,14 +2026,9 @@ test("browser_tests") {
         ]
       }
 
-      if (is_linux) {
-        data += [ "//testing/buildbot/filters/browser-side-navigation.linux.browser_tests.filter" ]
-      }
-
       if (is_win || is_linux) {
         sources += [ "../browser/nacl_host/test/nacl_gdb_browsertest.cc" ]
         data_deps += [ "//chrome/browser/nacl_host/test:mock_nacl_gdb" ]
-        data += [ "//testing/buildbot/filters/site-per-process.browser_tests.filter" ]
       }
       if (is_win) {
         # TODO(halyavin) NaCl on Windows can't open debug stub socket in