Implement <webview>.addContentScript/removeContentScript API [1]

extensions/browser/guest_view/web_view/web_view_content_script_manager.cc

+// Copyright 2015 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/browser/guest_view/web_view/web_view_content_script_manager.h"
+
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/browser_thread.h"
+#include "extensions/browser/declarative_user_script_manager.h"
+#include "extensions/browser/declarative_user_script_master.h"
+#include "extensions/browser/extension_system.h"
+#include "extensions/browser/guest_view/web_view/web_view_constants.h"
+#include "extensions/browser/guest_view/web_view/web_view_renderer_state.h"
+
+using content::BrowserThread;
+
+namespace extensions {
+
+WebViewContentScriptManager::WebViewContentScriptManager(
+    content::BrowserContext* browser_context)
+    : browser_context_(browser_context) {
+}
+
+WebViewContentScriptManager::~WebViewContentScriptManager() {
+}
+
+WebViewContentScriptManager* WebViewContentScriptManager::Get(
+    content::BrowserContext* browser_context) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  WebViewContentScriptManager* manager =
+      static_cast<WebViewContentScriptManager*>(browser_context->GetUserData(
+          webview::kWebViewContentScriptManagerKeyName));
+  if (!manager) {
+    manager = new WebViewContentScriptManager(browser_context);
+    browser_context->SetUserData(webview::kWebViewContentScriptManagerKeyName,
+                                 manager);
+  }
+  return manager;
+}
+
+void WebViewContentScriptManager::AddContentScripts(
+    int embedder_process_id,
+    int guest_view_instance_id,

[Fady Samuel, 2015/03/31 23:40:12]

nit: view_instance_id

[Xi Han, 2015/04/01 22:14:41]

Done.

+    const HostID& host_id,
+    const std::map<std::string, UserScript>& scripts) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  DeclarativeUserScriptMaster* master =
+      ExtensionSystem::Get(browser_context_)
+          ->declarative_user_script_manager()
+          ->GetDeclarativeUserScriptMasterByID(host_id);
+  CHECK(master);

[Fady Samuel, 2015/03/31 23:40:12]

Why is this a CHECK? Maybe DCHECK?

[Xi Han, 2015/04/01 22:14:41]

Done.

+
+  // We need to update WebViewRenderState in the IO thread if the guest exists.
+  std::set<int> ids_to_add;
+
+  GuestMapKey key =
+      std::pair<int, int>(embedder_process_id, guest_view_instance_id);

[Fady Samuel, 2015/03/31 23:40:12]

Call this the view_instance_id to match usage elsewhere.

[Xi Han, 2015/04/01 22:14:41]

Done.

+  GuestContentScriptMap::iterator iter = guest_content_script_map_.find(key);
+
+  // If there isn't any content script added for the given guest yet, insert the
+  // |key, scripts| to the |guest_content_script_map_| directly; otherwise,
+  // insert the |scripts| to the existing content script map of the guest.
+  if (iter == guest_content_script_map_.end()) {

[Fady Samuel, 2015/03/31 23:40:12]

This code is a bit difficult to read. How about creating a helper
AddContentScript(GuestMapKey key, const UserScript& script)?

[Xi Han, 2015/04/01 22:14:41]

Some changes are made to simply the for loop here, hopefully it improves the
readability of the code. 

+    guest_content_script_map_.insert(
+        std::pair<GuestMapKey, ContentScriptMap>(key, scripts));
+  } else {
+    ContentScriptMap& map = iter->second;
+    for (const std::pair<std::string, UserScript>& pair : scripts) {
+      auto map_iter = map.find(pair.first);
+      // If a content script has the same name as the new one, removes the old
+      // script first, and insert the new one.
+      if (map_iter != map.end()) {
+        master->RemoveScript(map_iter->second);
+        map.erase(map_iter);
+      }
+      map.insert(pair);
+    }
+  }
+
+  for (const std::pair<std::string, UserScript>& pair : scripts) {
+    ids_to_add.insert(pair.second.id());
+    master->AddScript(pair.second);
+  }
+
+  // Update WebViewRenderState in the IO thread.
+  if (!ids_to_add.empty()) {
+    content::BrowserThread::PostTask(
+        content::BrowserThread::IO, FROM_HERE,
+        base::Bind(&WebViewRendererState::AddContentScriptIDs,
+                   base::Unretained(WebViewRendererState::GetInstance()),
+                   embedder_process_id, guest_view_instance_id, ids_to_add));
+  }
+}
+
+void WebViewContentScriptManager::RemoveContentScripts(
+    int embedder_process_id,
+    int guest_view_instance_id,
+    const HostID& host_id,
+    std::vector<std::string>* script_name_list) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  GuestMapKey key =
+      std::pair<int, int>(embedder_process_id, guest_view_instance_id);
+  GuestContentScriptMap::iterator script_map_iter =
+      guest_content_script_map_.find(key);
+  if (script_map_iter == guest_content_script_map_.end())
+    return;
+
+  DeclarativeUserScriptMaster* master =
+      ExtensionSystem::Get(browser_context_)
+          ->declarative_user_script_manager()
+          ->GetDeclarativeUserScriptMasterByID(host_id);
+  CHECK(master);
+
+  // We need to update WebViewRenderState in the IO thread if the guest exists.
+  std::set<int> ids_to_delete;
+
+  std::vector<std::string> names_to_delete;
+  std::map<std::string, UserScript>& map = script_map_iter->second;
+  // If the |script_name_list| is empty, all the content scripts added by the
+  // guest will be removed; otherwise, removes the scripts in the
+  // |script_name_list|.
+  if (!script_name_list || script_name_list->empty()) {
+    for (const std::pair<std::string, UserScript>& iter : map)
+      names_to_delete.push_back(iter.first);
+  } else {
+    names_to_delete = *script_name_list;
+  }
+
+  for (const std::string& name : names_to_delete) {
+    ContentScriptMap::iterator iter = map.find(name);
+    if (iter == map.end())
+      continue;
+    const UserScript& script = iter->second;
+    ids_to_delete.insert(script.id());
+    master->RemoveScript(script);
+    map.erase(iter);
+  }
+
+  // Update WebViewRenderState in the IO thread.
+  if (!ids_to_delete.empty()) {
+    content::BrowserThread::PostTask(
+        content::BrowserThread::IO, FROM_HERE,
+        base::Bind(&WebViewRendererState::RemoveContentScriptIDs,
+                   base::Unretained(WebViewRendererState::GetInstance()),
+                   embedder_process_id, guest_view_instance_id, ids_to_delete));
+  }
+}
+
+std::set<int> WebViewContentScriptManager::GetContentScriptIdSet(

[Fady Samuel, 2015/03/31 23:40:12]

nit: GetContentScriptIDSet

[Xi Han, 2015/04/01 22:14:41]

Done.

+    int embedder_process_id,
+    int guest_view_instance_id) {
+  std::set<int> ids;
+
+  GuestMapKey key =
+      std::pair<int, int>(embedder_process_id, guest_view_instance_id);
+  GuestContentScriptMap::const_iterator iter =
+      guest_content_script_map_.find(key);
+  if (iter == guest_content_script_map_.end())
+    return ids;
+  const ContentScriptMap& map = iter->second;
+  for (const auto& pair : map)
+    ids.insert(pair.second.id());
+
+  return ids;
+}
+
+}  // namespace extensions