Introduce ScriptInjection in extensions/renderer to inject UserScripts

UserScriptSlave was responsible for too much, and the logic was getting
cluttered (which also made changes in, e.g.
https://codereview.chromium.org/288053002/ difficult to read, write, and
review). Refactor the logic to inject the scripts into a new class, so that
UserScriptSlave is pretty much just responsible for containing them.

BUG=373961

Review URL: https://codereview.chromium.org/284153006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@271532 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 107 insertions, 0 deletions

diff --git a/extensions/renderer/script_injection.h b/extensions/renderer/script_injection.h
new file mode 100644
index 0000000..813fbb4
--- /dev/null
+++ b/extensions/renderer/script_injection.h
@@ -0,0 +1,107 @@
+// 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.
+
+#ifndef EXTENSIONS_RENDERER_SCRIPT_INJECTION_H_
+#define EXTENSIONS_RENDERER_SCRIPT_INJECTION_H_
+
+#include <map>
+#include <set>
+#include <string>
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/timer/elapsed_timer.h"
+#include "extensions/common/user_script.h"
+
+class GURL;
+
+namespace blink {
+class WebFrame;
+}
+
+namespace extensions {
+class UserScriptSlave;
+
+// This class is a wrapper around a UserScript that knows how to inject itself
+// into a frame.
+class ScriptInjection {
+ public:
+  // Map of extensions IDs to the executing script paths.
+  typedef std::map<std::string, std::set<std::string> > ExecutingScriptsMap;
+
+  // A struct containing information about a script run.
+  struct ScriptsRunInfo {
+    ScriptsRunInfo();
+    ~ScriptsRunInfo();
+
+    // The number of CSS scripts injected.
+    size_t num_css;
+    // The number of JS scripts injected.
+    size_t num_js;
+    // A map of extension ids to executing script paths.
+    ExecutingScriptsMap executing_scripts;
+    // The elapsed time since the ScriptsRunInfo was constructed.
+    base::ElapsedTimer timer;
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(ScriptsRunInfo);
+  };
+
+  // Return the URL to use as the document url when checking permissions for
+  // script injection.
+  static GURL GetDocumentUrlForFrame(blink::WebFrame* frame);
+
+  ScriptInjection(scoped_ptr<UserScript> script,
+                  UserScriptSlave* user_script_slave);
+  ~ScriptInjection();
+
+  // Returns true if this ScriptInjection wants to run on the given |frame| at
+  // the given |run_location| (i.e., if this script would inject either JS or
+  // CSS).
+  bool WantsToRun(blink::WebFrame* frame,
+                  UserScript::RunLocation run_location,
+                  const GURL& document_url) const;
+
+  // Injects the script into the given |frame|, and updates |scripts_run_info|
+  // information about the run.
+  void Inject(blink::WebFrame* frame,
+              UserScript::RunLocation run_location,
+              ScriptsRunInfo* scripts_run_info) const;
+
+  const std::string& extension_id() { return extension_id_; }
+
+ private:
+  // Returns true if the script will inject [css|js] at the given
+  // |run_location|.
+  bool ShouldInjectJS(UserScript::RunLocation run_location) const;
+  bool ShouldInjectCSS(UserScript::RunLocation run_location) const;
+
+  // Injects the [css|js] scripts into the frame, and stores the results of
+  // the run in |scripts_run_info|.
+  void InjectJS(blink::WebFrame* frame, ScriptsRunInfo* scripts_run_info) const;
+  void InjectCSS(blink::WebFrame* frame, ScriptsRunInfo* scripts_run_info)
+      const;
+
+  // The UserScript this is injecting.
+  scoped_ptr<UserScript> script_;
+
+  // The associated extension's id. This is a safe const&, since it is owned by
+  // the |user_script_|.
+  const std::string& extension_id_;
+
+  // The associated UserScriptSlave.
+  // It's unfortunate that this is needed, but we use it to get the isolated
+  // world ids and the associated extensions.
+  // TODO(rdevlin.cronin): It would be nice to clean this up more.
+  UserScriptSlave* user_script_slave_;
+
+  // True if the script is a standalone script or emulates greasemonkey.
+  bool is_standalone_or_emulate_greasemonkey_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScriptInjection);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_RENDERER_SCRIPT_INJECTION_H_