Ok, here is a different approach at this change.

chrome/renderer/user_script_slave.cc

Index: chrome/renderer/user_script_slave.cc
diff --git a/chrome/renderer/user_script_slave.cc b/chrome/renderer/user_script_slave.cc
index 73f25378b210ac9a080d7701cbaeadfdccd55e85..68dec433471cfaedb7ea8e87babf001dbc009167 100644
--- a/chrome/renderer/user_script_slave.cc
+++ b/chrome/renderer/user_script_slave.cc
@@ -5,12 +5,15 @@
 #include "chrome/renderer/user_script_slave.h"
 
 #include "app/resource_bundle.h"
+#include "base/command_line.h"
 #include "base/histogram.h"
 #include "base/logging.h"
 #include "base/perftimer.h"
 #include "base/pickle.h"
 #include "base/shared_memory.h"
 #include "base/string_util.h"
+#include "chrome/common/child_process_logging.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "chrome/renderer/extension_groups.h"
@@ -111,6 +114,24 @@ bool UserScriptSlave::UpdateScripts(base::SharedMemoryHandle shared_memory) {
     }
   }
 
+  // Update the crash reporter with all loaded extensions. In single process,
+  // this has already been done in the browser code.
+  if (!CommandLine::ForCurrentProcess()->HasSwitch(switches::kSingleProcess)) {
+    std::vector<std::string> extension_ids;
+    for (size_t i = 0; i < num_scripts; ++i) {
+      DCHECK(!scripts_[i]->extension_id().empty());
+
+      // We must check this because there can be multiple scripts from a single
+      // extension. n^2, but meh, it's a small list.
+      if (std::find(extension_ids.begin(), extension_ids.end(),
+                    scripts_[i]->extension_id()) == extension_ids.end()) {
+        extension_ids.push_back(scripts_[i]->extension_id());
+      }
+    }
+
+    child_process_logging::SetActiveExtensions(extension_ids);
+  }
+
   return true;
 }