Prevent duplicate content script injection defined in manifest.json (reland)

extensions/renderer/user_script_injector.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 "extensions/renderer/user_script_injector.h"
 
 #include <tuple>
 #include <vector>
 
 #include "base/lazy_instance.h"
@@ skipping 62 matching lines @@
       blink::WebString::fromUTF8(source_piece.data(), source_piece.length());
 }
 
 blink::WebScriptSource GreasemonkeyApiJsString::GetSource() const {
   return blink::WebScriptSource(source_);
 }
 
 base::LazyInstance<GreasemonkeyApiJsString> g_greasemonkey_api =
     LAZY_INSTANCE_INITIALIZER;
 
+bool ShouldInjectScripts(const UserScript::FileList& scripts,
+                         const std::set<std::string>& injected_files) {
+  for (const std::unique_ptr<UserScript::File>& file : scripts) {
+    // Check if the script is already injected.
+    if (injected_files.count(file->url().path()) == 0) {
+      return true;
+    }
+  }
+  return false;
+}
+
 }  // namespace
 
 UserScriptInjector::UserScriptInjector(const UserScript* script,
                                        UserScriptSet* script_list,
                                        bool is_declarative)
     : script_(script),
       user_script_set_(script_list),
       script_id_(script_->id()),
       host_id_(script_->host_id()),
       is_declarative_(is_declarative),
@@ skipping 35 matching lines @@
 
 bool UserScriptInjector::IsUserGesture() const {
   return false;
 }
 
 bool UserScriptInjector::ExpectsResults() const {
   return false;
 }
 
 bool UserScriptInjector::ShouldInjectJs(
-    UserScript::RunLocation run_location) const {
+    UserScript::RunLocation run_location,
+    const std::set<std::string>& executing_scripts) const {
   return script_ && script_->run_location() == run_location &&
-         !script_->js_scripts().empty();
+         !script_->js_scripts().empty() &&
+         ShouldInjectScripts(script_->js_scripts(), executing_scripts);
 }
 
 bool UserScriptInjector::ShouldInjectCss(
-    UserScript::RunLocation run_location) const {
+    UserScript::RunLocation run_location,
+    const std::set<std::string>& injected_stylesheets) const {
   return script_ && run_location == UserScript::DOCUMENT_START &&
-         !script_->css_scripts().empty();
+         !script_->css_scripts().empty() &&
+         ShouldInjectScripts(script_->css_scripts(), injected_stylesheets);
 }
 
 PermissionsData::AccessType UserScriptInjector::CanExecuteOnFrame(
     const InjectionHost* injection_host,
     blink::WebLocalFrame* web_frame,
     int tab_id) const {
   // There is no harm in allowing the injection when the script is gone,
   // because there is nothing to inject.
   if (!script_)
     return PermissionsData::ACCESS_ALLOWED;
@@ skipping 30 matching lines @@
       web_frame, web_frame->document().url(), script_->match_about_blank());
 
   return injection_host->CanExecuteOnFrame(
       effective_document_url,
       content::RenderFrame::FromWebFrame(web_frame),
       tab_id,
       is_declarative_);
 }
 
 std::vector<blink::WebScriptSource> UserScriptInjector::GetJsSources(
-    UserScript::RunLocation run_location) const {
+    UserScript::RunLocation run_location,
+    std::set<std::string>* executing_scripts,
+    size_t* num_injected_js_scripts) const {
+  DCHECK(script_);
   std::vector<blink::WebScriptSource> sources;
-  if (!script_)
-    return sources;
 
   DCHECK_EQ(script_->run_location(), run_location);
 
   const UserScript::FileList& js_scripts = script_->js_scripts();
   sources.reserve(js_scripts.size() +
                   (script_->emulate_greasemonkey() ? 1 : 0));
-
   // Emulate Greasemonkey API for scripts that were converted to extension
   // user scripts.
   if (script_->emulate_greasemonkey())
     sources.push_back(g_greasemonkey_api.Get().GetSource());
+  for (const std::unique_ptr<UserScript::File>& file : js_scripts) {
+    const GURL& script_url = file->url();
+    // Check if the script is already injected.
+    if (executing_scripts->count(script_url.path()) != 0)
+      continue;
 
-  for (const std::unique_ptr<UserScript::File>& file : js_scripts) {
     sources.push_back(blink::WebScriptSource(
         user_script_set_->GetJsSource(*file, script_->emulate_greasemonkey()),
-        file->url()));
+        script_url));
+
+    (*num_injected_js_scripts) += 1;
+    executing_scripts->insert(script_url.path());
   }
 
   return sources;
 }
 
 std::vector<blink::WebString> UserScriptInjector::GetCssSources(
-    UserScript::RunLocation run_location) const {
+    UserScript::RunLocation run_location,
+    std::set<std::string>* injected_stylesheets,
+    size_t* num_injected_stylesheets) const {
+  DCHECK(script_);
   DCHECK_EQ(UserScript::DOCUMENT_START, run_location);
 
   std::vector<blink::WebString> sources;
-  if (!script_)
-    return sources;
 
   const UserScript::FileList& css_scripts = script_->css_scripts();
   sources.reserve(css_scripts.size());
-  for (const std::unique_ptr<UserScript::File>& file : script_->css_scripts())
+  for (const std::unique_ptr<UserScript::File>& file : script_->css_scripts()) {
+    const std::string& stylesheet_path = file->url().path();
+    // Check if the stylesheet is already injected.
+    if (injected_stylesheets->count(stylesheet_path) != 0)
+      continue;
+
     sources.push_back(user_script_set_->GetCssSource(*file));
+    (*num_injected_stylesheets) += 1;
+    injected_stylesheets->insert(stylesheet_path);
+  }
   return sources;
 }
 
-void UserScriptInjector::GetRunInfo(
-    ScriptsRunInfo* scripts_run_info,
-    UserScript::RunLocation run_location) const {
-  if (!script_)
-    return;
-
-  if (ShouldInjectJs(run_location)) {
-    const UserScript::FileList& js_scripts = script_->js_scripts();
-    scripts_run_info->num_js += js_scripts.size();
-    for (const std::unique_ptr<UserScript::File>& iter : js_scripts) {
-      scripts_run_info->executing_scripts[host_id_.id()].insert(
-          iter->url().path());
-    }
-  }
-
-  if (ShouldInjectCss(run_location))
-    scripts_run_info->num_css += script_->css_scripts().size();
-}
-
 void UserScriptInjector::OnInjectionComplete(
     std::unique_ptr<base::Value> execution_result,
     UserScript::RunLocation run_location,
     content::RenderFrame* render_frame) {}
 
 void UserScriptInjector::OnWillNotInject(InjectFailureReason reason,
                                          content::RenderFrame* render_frame) {
 }
 
 }  // namespace extensions