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..886ee2de0b673efb10cc272df05156c15f0a3432
--- /dev/null
+++ b/chrome/browser/extensions/active_script_controller.cc
@@ -0,0 +1,131 @@
+// 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 "base/stl_util.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_messages.h"
+#include "extensions/common/extension_set.h"
+#include "extensions/common/feature_switch.h"
+#include "extensions/common/permissions/permissions_data.h"
+#include "ipc/ipc_message_macros.h"
+
+namespace extensions {
+
+ActiveScriptController::ActiveScriptController(
+    content::WebContents* web_contents)
+    : content::WebContentsObserver(web_contents),
+      enabled_(FeatureSwitch::scripts_require_action()->IsEnabled()) {
+}
+
+ActiveScriptController::~ActiveScriptController() {
+  LogUMA();
+}
+
+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());
+  }
+}
+
+void ActiveScriptController::OnAdInjectionDetected(
+    const std::vector<std::string> ad_injectors) {
+  size_t num_preventable_ad_injectors =
+      base::STLSetIntersection<std::set<std::string> >(
+          ad_injectors, extensions_executing_scripts_).size();
+
+  UMA_HISTOGRAM_COUNTS_100(
+      "Extensions.ActiveScriptController.PreventableAdInjectors",
+      num_preventable_ad_injectors);
+  UMA_HISTOGRAM_COUNTS_100(
+      "Extensions.ActiveScriptController.PreventableAdInjectors",
+      ad_injectors.size() - num_preventable_ad_injectors);
+}
+
+ExtensionAction* ActiveScriptController::GetActionForExtension(
+    const Extension* extension) {
+  if (!enabled_ || 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()) {
+    action->set_default_icon(
+        make_scoped_ptr(new ExtensionIconSet(action_info->default_icon)));
+  }
+
+  active_script_actions_[extension->id()] = action;
+  return action.get();
+}
+
+LocationBarController::Action ActiveScriptController::OnClicked(
+    const Extension* extension) {
+  DCHECK(extensions_executing_scripts_.count(extension->id()) > 0);
+  return LocationBarController::ACTION_NONE;
+}
+
+void ActiveScriptController::OnNavigated() {
+  LogUMA();
+  extensions_executing_scripts_.clear();
+}
+
+bool ActiveScriptController::OnMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(ActiveScriptController, message)
+    IPC_MESSAGE_HANDLER(ExtensionHostMsg_NotifyExtensionScriptExecution,
+                        OnNotifyExtensionScriptExecution)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void ActiveScriptController::OnNotifyExtensionScriptExecution(
+    const std::string& extension_id,
+    int page_id) {
+  if (!Extension::IdIsValid(extension_id)) {
+    NOTREACHED() << "'" << extension_id << "' is not a valid id.";
+    return;
+  }
+  NotifyScriptExecuting(extension_id, page_id);
+}
+
+void ActiveScriptController::LogUMA() const {
+  UMA_HISTOGRAM_COUNTS_100(
+      "Extensions.ActiveScriptController.ShownActiveScriptsOnPage",
+      extensions_executing_scripts_.size());
+}
+
+}  // namespace extensions