Refactoring: de-couple Extensions from "script injection System" [render side] : 1

extensions/browser/script_executor.cc

Index: extensions/browser/script_executor.cc
diff --git a/extensions/browser/script_executor.cc b/extensions/browser/script_executor.cc
index ac3e671b9a48c056a0344f16c51a92ab5b2a2372..d135be82434599d79fb97d7f33dd84d299b62904 100644
--- a/extensions/browser/script_executor.cc
+++ b/extensions/browser/script_executor.cc
@@ -14,6 +14,7 @@
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/script_execution_observer.h"
 #include "extensions/common/extension_messages.h"
+#include "extensions/common/host_id.h"
 #include "ipc/ipc_message.h"
 #include "ipc/ipc_message_macros.h"
 
@@ -122,6 +123,7 @@ void ScriptExecutor::ExecuteScript(const std::string& extension_id,
                                    ScriptExecutor::WorldType world_type,
                                    ScriptExecutor::ProcessType process_type,
                                    const GURL& webview_src,
+                                   int instance_id,
                                    const GURL& file_url,
                                    bool user_gesture,
                                    ScriptExecutor::ResultType result_type,
@@ -143,6 +145,8 @@ void ScriptExecutor::ExecuteScript(const std::string& extension_id,
   params.run_at = static_cast<int>(run_at);
   params.in_main_world = (world_type == MAIN_WORLD);
   params.is_web_view = (process_type == WEB_VIEW_PROCESS);
+  params.instance_id = params.is_web_view ? instance_id :

[Devlin, 2015/02/04 17:01:14]

It seems odd that you pass in an instance id from the tabs api, only to ignore
it here.  I think it'd be cleaner to just assign params.instance_id to the
passed in instance id, and add a DCHECK that either it's a webview process or
the instance id is 0.

[Xi Han, 2015/02/05 16:06:20]

The webview.executecode api also needs to call this ExecuteScript function, so
the instance_id is passed here to make scripts injection to a separate isolated
world.

[Devlin, 2015/02/06 00:28:40]

Right. What I am suggesting is:
params.instance_id = instance_id;
// Only webviews should have custom instance ids.
DCHECK(instance_id == Host::kDefaultInstanceId || params.is_web_view);

Since the each execute code function passes in an instance id, this should be
correct, and this way we know if it fails.

[Xi Han, 2015/02/06 17:21:45]

Good idea, I misunderstood your last comments. Updated.

+      Host::kDefaultInstanceId;
   params.webview_src = webview_src;
   params.file_url = file_url;
   params.wants_result = (result_type == JSON_SERIALIZED_RESULT);