[cleanup] Fix uses of deprecated *Value methods in content_shell

Instead of the deprecated argumentless Int32Value and BooleanValue
functions, it now uses the Context versions which return MaybeLocals.
Since this is for testing, we just force the results to their respective
types and crash if not possible.

Change-Id: I4a1b83640bdd64e3d7b81c5e21e1c8e0e89eb900
Reviewed-on: https://chromium-review.googlesource.com/1151987
Reviewed-by: Peter Beverloo <[email protected]>
Commit-Queue: Dan Elphick <[email protected]>
Cr-Commit-Position: refs/heads/master@{#578619}
diff --git a/content/shell/test_runner/test_runner.h b/content/shell/test_runner/test_runner.h
index ee22feb..767d61a 100644
--- a/content/shell/test_runner/test_runner.h
+++ b/content/shell/test_runner/test_runner.h
@@ -285,7 +285,7 @@
   void SetXSSAuditorEnabled(bool enabled);
   void SetAllowUniversalAccessFromFileURLs(bool allow);
   void SetAllowFileAccessFromFileURLs(bool allow);
-  void OverridePreference(const std::string& key, v8::Local<v8::Value> value);
+  void OverridePreference(gin::Arguments* arguments);
 
   // Modify accept_languages in RendererPreferences.
   void SetAcceptLanguages(const std::string& accept_languages);