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 "base/lazy_instance.h"
+#include "base/memory/linked_ptr.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/navigation_details.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_observer.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/guest_view_manager.h"
+#include "extensions/browser/guest_view/web_view/web_view_constants.h"
+#include "extensions/browser/guest_view/web_view/web_view_guest.h"
+#include "extensions/browser/guest_view/web_view/web_view_renderer_state.h"
+
+using content::BrowserThread;
+
+namespace {
+bool RemoveContentScriptsForGuest(content::BrowserContext* browser_context,
+                                  HostID host_id,
+                                  content::WebContents* embedder_web_contents,
+                                  content::WebContents* guest_web_contents) {
+  auto guest = extensions::WebViewGuest::FromWebContents(guest_web_contents);
+  if (!guest)
+    return false;
+
+  extensions::WebViewContentScriptManager* manager =
+      extensions::WebViewContentScriptManager::Get(browser_context);
+  if (!manager)
+    return false;
+
+  manager->RemoveContentScripts(embedder_web_contents,
+                                guest->view_instance_id(), host_id,
+                                std::vector<std::string>());
+  return true;

[Fady Samuel, 2015/04/10 16:16:04]

I think you should return false here too to allow ForEachGuest to iterate to all
other guests.

[Xi Han, 2015/04/10 18:27:07]

Done.

+}
+}
+
+namespace extensions {
+
+// This observer ensures that the content scripts added by the guest are removed
+// when its embedder goes away.
+class WebViewContentScriptManager::OwnerWebContentsObserver
+    : public content::WebContentsObserver {
+ public:
+  OwnerWebContentsObserver(content::WebContents* embedder_web_contents,
+                           const HostID& host_id,
+                           WebViewContentScriptManager* manager)
+      : WebContentsObserver(embedder_web_contents),
+        host_id_(host_id),
+        web_view_content_script_manager_(manager) {}
+  ~OwnerWebContentsObserver() override {}
+
+  // WebContentsObserver:
+  void WebContentsDestroyed() override {
+    // If the embedder is destroyed then remove all the content scripts of the
+    // guest.
+    RemoveContentScripts();
+  }
+  void DidNavigateMainFrame(
+      const content::LoadCommittedDetails& details,
+      const content::FrameNavigateParams& params) override {
+    // If the embedder navigates to a different page then destroy the guest.
+    if (details.is_navigation_to_different_page())
+      RemoveContentScripts();
+  }
+  void RenderProcessGone(base::TerminationStatus status) override {
+    // If the embedder crashes, then destroy the guest.
+    RemoveContentScripts();
+  }
+
+ private:
+  void RemoveContentScripts() {
+    web_view_content_script_manager_->RemoveContentScripts(web_contents(),
+                                                           host_id_);
+  }
+
+  HostID host_id_;
+  WebViewContentScriptManager* web_view_content_script_manager_;
+
+  DISALLOW_COPY_AND_ASSIGN(OwnerWebContentsObserver);
+};
+
+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(
+    content::WebContents* embedder_web_contents,
+    int view_instance_id,
+    const HostID& host_id,
+    const std::map<std::string, UserScript>& scripts) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(embedder_web_contents);
+
+  DeclarativeUserScriptMaster* master =
+      ExtensionSystem::Get(browser_context_)
+          ->declarative_user_script_manager()
+          ->GetDeclarativeUserScriptMasterByID(host_id);
+  DCHECK(master);
+
+  // We need to update WebViewRenderState in the IO thread if the guest exists.
+  std::set<int> ids_to_add;
+
+  int embedder_process_id =
+      embedder_web_contents->GetRenderProcessHost()->GetID();
+  GuestMapKey key = std::pair<int, int>(embedder_process_id, view_instance_id);
+  GuestContentScriptMap::iterator iter = guest_content_script_map_.find(key);
+
+  // Step 1: finds the entry in guest_content_script_map_ by the given |key|.
+  // If there isn't any content script added for the given guest yet, insert an
+  // empty map first.
+  if (iter == guest_content_script_map_.end()) {
+    iter = guest_content_script_map_.insert(
+        iter, std::pair<GuestMapKey, ContentScriptMap>(
+                  key, std::map<std::string, UserScript>()));
+  }
+
+  // Step 2: updates the guest_content_script_map_, and adds content scripts to
+  // the master.
+  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);

[Devlin, 2015/04/10 16:04:32]

What happens when a WebUI has two webviews, and adds the same content script to
each?  Should we really remove it from the master?

[Fady Samuel, 2015/04/10 16:16:04]

This API doesn't allow two webviews to share a content script rule. If the same
script is injected into two webviews they'd be two different UserScripts, I
think. Is that correct Xi?

[Xi Han, 2015/04/10 18:27:07]

We will create two different user scripts for them. Currently, we only support
adding rules by specifying the entire rule, while don't support adding rule by
name. Even for the same name ruleA, we treat <webview1>.ruleA as a different
rule as <webview2>.ruleA.

+      map.erase(map_iter);
+    }
+    map.insert(pair);
+    ids_to_add.insert(pair.second.id());
+    master->AddScript(pair.second);
+  }
+
+  // Step 3: creates owner web contents observer for the given
+  // |embedder_web_contents| if it doesn't exist.
+  auto observers_map_iter =
+      owner_web_contents_observer_map_.find(embedder_web_contents);
+  if (observers_map_iter == owner_web_contents_observer_map_.end()) {
+    linked_ptr<OwnerWebContentsObserver> observer(
+        new OwnerWebContentsObserver(embedder_web_contents, host_id, this));
+    owner_web_contents_observer_map_[embedder_web_contents] = observer;
+  }
+
+  // Step 4: updates 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, view_instance_id, ids_to_add));
+  }
+}
+
+void WebViewContentScriptManager::RemoveContentScripts(
+    content::WebContents* embedder_web_contents,
+    int view_instance_id,
+    const HostID& host_id,
+    const std::vector<std::string>& script_name_list) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  int embedder_process_id =
+      embedder_web_contents->GetRenderProcessHost()->GetID();
+  GuestMapKey key = std::pair<int, int>(embedder_process_id, 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;
+
+  // Step 1: removed content scripts from |master| and updates
+  // |guest_content_script_map_|
+  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.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);
+  }
+
+  // Step 2: 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, view_instance_id, ids_to_delete));
+  }
+}
+
+void WebViewContentScriptManager::RemoveContentScripts(
+    content::WebContents* embedder_web_contents,
+    const HostID& host_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  // Step 1: removes content scripts of all the guests embedded.
+  auto guest_view_manager =
+      GuestViewManager::FromBrowserContext(browser_context_);
+  guest_view_manager->ForEachGuest(
+      embedder_web_contents,
+      base::Bind(&RemoveContentScriptsForGuest, browser_context_, host_id,
+                 embedder_web_contents));
+
+  // Step 2: removes the observer of the given |embedder_web_contents|.
+  owner_web_contents_observer_map_.erase(embedder_web_contents);
+}
+
+std::set<int> WebViewContentScriptManager::GetContentScriptIDSet(
+    int embedder_process_id,
+    int view_instance_id) {
+  std::set<int> ids;
+
+  GuestMapKey key = std::pair<int, int>(embedder_process_id, 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