Introduce ActiveScriptController; track active extension scripts

chrome/browser/extensions/active_script_controller.cc

Index: chrome/browser/extensions/active_script_controller.cc
diff --git a/chrome/browser/extensions/active_script_controller.cc b/chrome/browser/extensions/active_script_controller.cc
new file mode 100644
index 0000000000000000000000000000000000000000..53db5b39d674a2e26c9d6a0b6b0017712d7d4abe
--- /dev/null
+++ b/chrome/browser/extensions/active_script_controller.cc
@@ -0,0 +1,105 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/extensions/active_script_controller.h"
+
+#include "base/metrics/histogram.h"
+#include "chrome/browser/extensions/extension_action.h"
+#include "chrome/common/extensions/api/extension_action/action_info.h"
+#include "content/public/browser/navigation_controller.h"
+#include "content/public/browser/navigation_entry.h"
+#include "content/public/browser/web_contents.h"
+#include "extensions/browser/extension_registry.h"
+#include "extensions/common/extension.h"
+#include "extensions/common/extension_set.h"
+#include "extensions/common/feature_switch.h"
+#include "extensions/common/permissions/permissions_data.h"
+
+namespace extensions {
+
+namespace {
+
+void LogActiveScriptUMA(size_t number_of_active_scripts) {
+  UMA_HISTOGRAM_COUNTS_100(
+      "Extensions.ActiveScriptController.ShownActiveScriptsOnPage",
+      number_of_active_scripts);
+}
+
+}
+
+ActiveScriptController::ActiveScriptController(
+    content::WebContents* web_contents)
+    : web_contents_(web_contents),
+      enabled_(FeatureSwitch::scripts_require_action()->IsEnabled()) {
+}
+
+ActiveScriptController::~ActiveScriptController() {
+  LogActiveScriptUMA(extensions_executing_scripts_.size());

[not at google - send to devlin, 2014/05/08 20:47:09]

you should only log UMA if it's enabled

[Devlin, 2014/05/08 23:01:00]

Free (still good data) even if not enabled.

+}
+
+void ActiveScriptController::NotifyScriptExecuting(
+    const std::string& extension_id, int page_id) {
+  if (extensions_executing_scripts_.count(extension_id) ||
+      web_contents_->GetController().GetVisibleEntry()->GetPageID()
+          != page_id) {
+    return;
+  }
+
+  const Extension* extension =
+      ExtensionRegistry::Get(web_contents_->GetBrowserContext())
+          ->enabled_extensions().GetByID(extension_id);
+  if (extension &&
+      PermissionsData::RequiresActionForScriptExecution(extension)) {
+    extensions_executing_scripts_.insert(extension_id);
+    LocationBarController::NotifyChange(web_contents_);
+  }
+}
+
+bool ActiveScriptController::HasActionForExtensionId(
+    const std::string& extension_id) {
+  return extensions_executing_scripts_.count(extension_id) > 0;

[not at google - send to devlin, 2014/05/08 20:47:09]

If this isn't |enabled_| then you'll be giving misleading data to callers.

+}
+
+ExtensionAction* ActiveScriptController::GetActionForExtension(
+    const Extension* extension) {

[not at google - send to devlin, 2014/05/08 20:47:09]

check |enabled_|

[Devlin, 2014/05/08 23:01:00]

Done.

+  if (extensions_executing_scripts_.count(extension->id()) == 0)
+    return NULL;  // No action for this extension.
+
+  ActiveScriptMap::iterator existing =
+      active_script_actions_.find(extension->id());
+  if (existing != active_script_actions_.end())
+    return existing->second.get();
+
+  linked_ptr<ExtensionAction> action(
+      new ExtensionAction(extension->id(),
+                          ActionInfo::TYPE_PAGE,
+                          ActionInfo()));
+  action->SetTitle(ExtensionAction::kDefaultTabId, extension->name());
+  action->SetIsVisible(ExtensionAction::kDefaultTabId, true);
+
+  const ActionInfo* action_info = ActionInfo::GetPageActionInfo(extension);
+  if (!action_info)
+    action_info = ActionInfo::GetBrowserActionInfo(extension);
+
+  if (action_info && !action_info->default_icon.empty()) {
+    scoped_ptr<ExtensionIconSet> icon_set(
+        new ExtensionIconSet(action_info->default_icon));
+    action->set_default_icon(icon_set.Pass());

[not at google - send to devlin, 2014/05/08 20:47:09]

easier on the eyes:

action->set_default_icon(
    make_scoped_ptr(new ExtensionIconSet(action_info->default_icon));

[Devlin, 2014/05/08 23:01:00]

Done.

+  }
+
+  active_script_actions_[extension->id()] = action;
+  return action.get();
+}
+
+LocationBarController::Action ActiveScriptController::OnClicked(
+    const Extension* extension) {

[not at google - send to devlin, 2014/05/08 20:47:09]

DCHECK(enabled_)

[Devlin, 2014/05/08 23:01:00]

We can get OnClicked even if not enabled, since the OnClick() goes through the
location bar controller into each of the providers (since actions may be
grouped).

+  return LocationBarController::ACTION_NONE;
+}
+
+void ActiveScriptController::OnNavigated() {
+  LogActiveScriptUMA(extensions_executing_scripts_.size());

[not at google - send to devlin, 2014/05/08 20:47:09]

only log UMA if enable

Generally there is so much checking of enabled, and it will be so easy for this
to regress, and it has issues... need to step back and have a higher-level look
at this.

[Devlin, 2014/05/08 23:01:00]

UMA if not enabled is fine.  Only need to check enabled once.

+  extensions_executing_scripts_.clear();
+}
+
+}  // namespace extensions