Ensure only one instance of AutomationInternalCustomBindings for background page extensions

chrome/renderer/extensions/automation_internal_custom_bindings.cc

 // 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/renderer/extensions/automation_internal_custom_bindings.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/values.h"
 #include "chrome/common/extensions/api/automation_api_constants.h"
 #include "chrome/common/extensions/chrome_extension_messages.h"
 #include "chrome/common/extensions/manifest_handlers/automation.h"
 #include "content/public/renderer/render_frame.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/public/renderer/render_view.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/manifest.h"
+#include "extensions/common/manifest_handlers/background_info.h"
 #include "extensions/renderer/extension_bindings_system.h"
 #include "extensions/renderer/script_context.h"
 #include "ipc/message_filter.h"
 #include "ui/accessibility/ax_enums.h"
 #include "ui/accessibility/ax_node.h"
 #include "ui/gfx/geometry/rect_conversions.h"
 
 namespace extensions {
 
 namespace {
@@ skipping 383 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(AutomationMessageFilter);
 };
 
 AutomationInternalCustomBindings::AutomationInternalCustomBindings(
     ScriptContext* context,
     ExtensionBindingsSystem* bindings_system)
     : ObjectBackedNativeHandler(context),
       is_active_profile_(true),
       tree_change_observer_overall_filter_(0),
-      bindings_system_(bindings_system) {
-// It's safe to use base::Unretained(this) here because these bindings
-// will only be called on a valid AutomationInternalCustomBindings instance
-// and none of the functions have any side effects.
+      bindings_system_(bindings_system),
+      should_ignore_context_(false) {
+  // We will ignore this instance if the extension has a background page and
+  // this context is not that background page. In all other cases, we will have
+  // multiple instances floating around in the same process.
+  if (context && context->extension()) {
+    const GURL background_page_url =
+        extensions::BackgroundInfo::GetBackgroundURL(context->extension());
+    should_ignore_context_ = background_page_url != "" &&
+        background_page_url != context->url();
+  }
+
+  // It's safe to use base::Unretained(this) here because these bindings
+  // will only be called on a valid AutomationInternalCustomBindings instance
+  // and none of the functions have any side effects.
 #define ROUTE_FUNCTION(FN)                                        \
   RouteFunction(#FN, "automation",                                \
                 base::Bind(&AutomationInternalCustomBindings::FN, \
                            base::Unretained(this)))
   ROUTE_FUNCTION(IsInteractPermitted);
   ROUTE_FUNCTION(GetSchemaAdditions);
   ROUTE_FUNCTION(GetRoutingID);
   ROUTE_FUNCTION(StartCachingAccessibilityTrees);
   ROUTE_FUNCTION(DestroyAccessibilityTree);
   ROUTE_FUNCTION(AddTreeChangeObserver);
@@ skipping 319 matching lines @@
 }
 
 void AutomationInternalCustomBindings::GetRoutingID(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   int routing_id = context()->GetRenderFrame()->GetRenderView()->GetRoutingID();
   args.GetReturnValue().Set(v8::Integer::New(GetIsolate(), routing_id));
 }
 
 void AutomationInternalCustomBindings::StartCachingAccessibilityTrees(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
+  if (should_ignore_context_)
+    return;
+
   if (!message_filter_)
     message_filter_ = new AutomationMessageFilter(this);
 }
 
 void AutomationInternalCustomBindings::GetSchemaAdditions(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   v8::Local<v8::Object> additions = v8::Object::New(GetIsolate());
 
   v8::Local<v8::Object> name_from_type(v8::Object::New(GetIsolate()));
   for (int i = ui::AX_NAME_FROM_NONE; i <= ui::AX_NAME_FROM_LAST; ++i) {
@@ skipping 608 matching lines @@
     for (auto id : ids)
       nodes->AppendInteger(id);
     args.Append(std::move(nodes));
   }
 
   bindings_system_->DispatchEventInContext("automationInternal.onNodesRemoved",
                                            &args, nullptr, context());
 }
 
 }  // namespace extensions