Enable script bubble by default on all but mac.

chrome/browser/extensions/script_bubble_controller.cc

Index: chrome/browser/extensions/script_bubble_controller.cc
diff --git a/chrome/browser/extensions/script_bubble_controller.cc b/chrome/browser/extensions/script_bubble_controller.cc
index 67c6593e3ae904d3770b245e9372d843b71ad9ee..a4f76cee55ebef7df9e04559a30560f57fbb171b 100644
--- a/chrome/browser/extensions/script_bubble_controller.cc
+++ b/chrome/browser/extensions/script_bubble_controller.cc
@@ -13,6 +13,7 @@
 #include "chrome/browser/extensions/location_bar_controller.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/extensions/extension.h"
+#include "content/public/browser/navigation_details.h"
 
 namespace extensions {
 
@@ -40,7 +41,7 @@ void ScriptBubbleController::OnScriptsExecuted(
     // those are effectively not installed from the user's point of view.
     const Extension* extension =
         extension_service->extensions()->GetByID(i->first);
-    if (extension->ShouldDisplayInExtensionSettings())
+    if (extension && extension->ShouldDisplayInExtensionSettings())
       changed |= extensions_running_scripts_.insert(i->first).second;
   }
 
@@ -51,10 +52,18 @@ void ScriptBubbleController::OnScriptsExecuted(
 void ScriptBubbleController::DidNavigateMainFrame(
     const content::LoadCommittedDetails& details,
     const content::FrameNavigateParams& params) {
+  if (!details.is_navigation_to_different_page())
+    return;
   extensions_running_scripts_.clear();
   UpdateScriptBubble();
 }
 
+void ScriptBubbleController::OnExtensionUnloaded(
+    const std::string& extension_id) {
+  if (extensions_running_scripts_.erase(extension_id) == 1)
+    UpdateScriptBubble();
+}
+
 Profile* ScriptBubbleController::profile() const {
   return Profile::FromBrowserContext(web_contents()->GetBrowserContext());
 }