[Extensions] Remove the source_tab_id property on API request messages

extensions/browser/extension_function.h

Index: extensions/browser/extension_function.h
diff --git a/extensions/browser/extension_function.h b/extensions/browser/extension_function.h
index 89ac5a2d24c149d14dea8c9a73a219e56acb0cef..95db5b7c19c804ee8136dc77b123a66676e4364e 100644
--- a/extensions/browser/extension_function.h
+++ b/extensions/browser/extension_function.h
@@ -296,9 +296,6 @@ class ExtensionFunction
     response_callback_ = callback;
   }
 
-  void set_source_tab_id(int source_tab_id) { source_tab_id_ = source_tab_id; }
-  int source_tab_id() const { return source_tab_id_; }
-
   void set_source_context_type(extensions::Feature::Context type) {
     source_context_type_ = type;
   }
@@ -465,9 +462,6 @@ class ExtensionFunction
   // is invoked.
   extensions::functions::HistogramValue histogram_value_;
 
-  // The ID of the tab triggered this function call, or -1 if there is no tab.
-  int source_tab_id_;
-
   // The type of the JavaScript context where this call originated.
   extensions::Feature::Context source_context_type_;