Allow omitting optional parameters for Extensions API functions

chrome/renderer/extensions/chrome_v8_context.cc

Index: chrome/renderer/extensions/chrome_v8_context.cc
diff --git a/chrome/renderer/extensions/chrome_v8_context.cc b/chrome/renderer/extensions/chrome_v8_context.cc
index 98b0c077573cf934e0882ad1b7638516bdab2707..3eaa841ae958cfb4c16032252133264f6bbed12c 100644
--- a/chrome/renderer/extensions/chrome_v8_context.cc
+++ b/chrome/renderer/extensions/chrome_v8_context.cc
@@ -20,6 +20,7 @@ const char kChromeHidden[] = "chromeHidden";
 
 #ifndef NDEBUG
 const char kValidateCallbacks[] = "validateCallbacks";
+const char kValidateAPI[] = "validateAPI";
 #endif
 
 }  // namespace
@@ -56,8 +57,11 @@ v8::Handle<v8::Value> ChromeV8Context::GetOrCreateChromeHidden(
 #ifndef NDEBUG
     // Tell schema_generated_bindings.js to validate callbacks and events
     // against their schema definitions.
-    v8::Local<v8::Object>::Cast(hidden)
-        ->Set(v8::String::New(kValidateCallbacks), v8::True());
+    v8::Local<v8::Object>::Cast(hidden)->Set(
+        v8::String::New(kValidateCallbacks), v8::True());
+    // Tell schema_generated_bindings.js to validate API for ambiguity.
+    v8::Local<v8::Object>::Cast(hidden)->Set(
+        v8::String::New(kValidateAPI), v8::True());
 #endif
   }