Use FrameIsAd to decide whether to isolate a frame in TopDocumentIsolation mode.

content/DEPS

 # Do NOT add chrome to the list below. We shouldn't be including files
 # from src/chrome in src/content.
 include_rules = [
   # The subdirectories in content/ will manually allow their own include
   # directories in content/ so we disallow all of them.
   "-content",
   "+content/app/resources/grit/content_resources.h",
   "+content/common",
   "+content/grit",
   "+content/public/common",
   "+content/public/test",
   "+content/test",
 
   "+blink/public/resources/grit",
 
   "+cc",
   "-cc/blink",
 
   "-components",
   # Content can depend on components that are:
   #   1) related to the implementation of the web platform
   #   2) shared code between third_party/WebKit and content
   # It should not depend on chrome features or implementation details, i.e. the
   # original components/ directories which was code split out from chrome/ to be
   # shared with iOS. This includes, but isn't limited to, browser features such
   # as autofill or extensions, and chrome implementation details such as
   # settings, packaging details, installation or crash reporting.
+  "+components/variations",
 
   "+crypto",
   "+grit/blink_resources.h",
   "+grit/content_strings.h",
 
   "+dbus",
   "+gpu",
   "+media",
   "+mojo/common",
   "+mojo/edk/embedder",
@@ skipping 80 matching lines @@
   "+jni",
 ]
 
 # content -> content/shell dependency is not allowed, except for browser tests.
 specific_include_rules = {
   ".*_browsertest[a-z_]*\.(cc|h)": [
     "+content/shell/browser",
     "+content/shell/common",
   ],
 }