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 67 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,
+                         std::set<std::string>* injected_files) {

[Devlin, 2016/09/07 18:22:40]

nit: const & for injected files

[catmullings, 2016/09/07 18:56:31]

Done.

+  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),
       script_id_(script_->id()),
       host_id_(script_->host_id()),
       is_declarative_(is_declarative),
       user_script_set_observer_(this) {
@@ skipping 34 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,
+    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,
+    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());
   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;
     base::StringPiece script_content = file->GetContent();
     blink::WebString source;
     if (script_->emulate_greasemonkey()) {
       // We add this dumb function wrapper for user scripts to emulate what
       // Greasemonkey does. |script_content| becomes:
       // concat(kUserScriptHead, script_content, kUserScriptTail).
       std::string content;
       content.reserve(strlen(kUserScriptHead) + script_content.length() +
                       strlen(kUserScriptTail));
       content.append(kUserScriptHead);
       script_content.AppendToString(&content);
       content.append(kUserScriptTail);
       // TODO(lazyboy): |content| is copied to |source|, should be avoided.
       // Investigate if we can leverage WebString's cheap copying mechanism
       // somehow.
       source = blink::WebString::fromUTF8(content);
     } else {
       source = blink::WebString::fromUTF8(script_content.data(),
                                           script_content.length());
     }
-    sources.push_back(blink::WebScriptSource(source, file->url()));
+    sources.push_back(blink::WebScriptSource(source, script_url));
+    (*num_injected_js_scripts) += 1;
+    (*executing_scripts).insert(script_url.path());
   }
-
   // Emulate Greasemonkey API for scripts that were converted to extension
   // user scripts.
   if (script_->emulate_greasemonkey())
     sources.insert(sources.begin(), g_greasemonkey_api.Get().GetSource());
 
   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()) {
+    const std::string stylesheet_path = file->url().path();

[Devlin, 2016/09/07 18:22:40]

nit: no need to copy here, so const std::string&

[catmullings, 2016/09/07 18:56:31]

Done.

[catmullings, 2016/09/07 18:56:31]

Yup, didn't mean to drop the &.

+    // Check if the stylesheet is already injected.
+    if ((*injected_stylesheets).count(stylesheet_path) != 0)
+      continue;
+
     // TODO(lazyboy): |css_content| string is copied into blink::WebString for
     // every frame in the current renderer process. Avoid the copy, possibly by
     // only performing the copy once.
     base::StringPiece css_content = file->GetContent();
     sources.push_back(
         blink::WebString::fromUTF8(css_content.data(), css_content.length()));
+    (*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