Encapsulate CSS selector declarative content condition tracking

chrome/browser/extensions/api/declarative_content/chrome_content_rules_registry.cc

 // Copyright (c) 2012 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 "chrome/browser/extensions/api/declarative_content/chrome_content_rules_registry.h"
 
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/extensions/api/declarative_content/content_action.h"
 #include "chrome/browser/extensions/api/declarative_content/content_condition.h"
 #include "chrome/browser/extensions/api/declarative_content/content_constants.h"
-#include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/extensions/extension_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_iterator.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_source.h"
-#include "content/public/browser/render_process_host.h"
 #include "content/public/browser/web_contents.h"
 #include "extensions/browser/api/declarative/rules_registry_service.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/extension_system.h"
-#include "extensions/common/extension_messages.h"
 
 using url_matcher::URLMatcherConditionSet;
 
 namespace extensions {
 
+template <class Func>
+void ChromeContentRulesRegistry::ForEachWebContents(const Func& func) {
+  for (chrome::BrowserIterator it; !it.done(); it.Next()) {
+    Browser* browser = *it;
+    if (!ManagingRulesForBrowserContext(browser->profile()))
+      continue;
+
+    for (int i = 0, tab_count = browser->tab_strip_model()->count();
+         i < tab_count; ++i) {
+      func(browser->tab_strip_model()->GetWebContentsAt(i));
+    }
+  }
+}
+
 ChromeContentRulesRegistry::ChromeContentRulesRegistry(
     content::BrowserContext* browser_context,
     RulesCacheDelegate* cache_delegate)
     : ContentRulesRegistry(browser_context,
                            declarative_content_constants::kOnPageChanged,
                            content::BrowserThread::UI,
                            cache_delegate,
-                           RulesRegistryService::kDefaultRulesRegistryID) {
+                           RulesRegistryService::kDefaultRulesRegistryID),
+      css_condition_tracker_(browser_context, this) {
   extension_info_map_ = ExtensionSystem::Get(browser_context)->info_map();
 
+  // Set up rule tracking for any existing WebContents.
+  ForEachWebContents([this](content::WebContents* contents) {
+    TrackRulesForWebContents(contents);
+  });
+
   registrar_.Add(this,
-                 content::NOTIFICATION_RENDERER_PROCESS_CREATED,
-                 content::NotificationService::AllBrowserContextsAndSources());
+                 chrome::NOTIFICATION_TAB_ADDED,
+                 content::NotificationService::AllSources());
   registrar_.Add(this,
                  content::NOTIFICATION_WEB_CONTENTS_DESTROYED,
                  content::NotificationService::AllBrowserContextsAndSources());
 }
 
 void ChromeContentRulesRegistry::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
   switch (type) {
-    case content::NOTIFICATION_RENDERER_PROCESS_CREATED: {
-      content::RenderProcessHost* process =
-          content::Source<content::RenderProcessHost>(source).ptr();
-      InstructRenderProcessIfSameBrowserContext(process);
+    case chrome::NOTIFICATION_TAB_ADDED: {
+      content::WebContents* contents =
+          content::Details<content::WebContents>(details).ptr();
+      TrackRulesForWebContents(contents);
       break;
     }
     case content::NOTIFICATION_WEB_CONTENTS_DESTROYED: {
       content::WebContents* tab =
           content::Source<content::WebContents>(source).ptr();
       // Note that neither non-tab WebContents nor tabs from other browser
       // contexts will be in the map.
       active_rules_.erase(tab);
-      matching_css_selectors_.erase(tab);
       break;
     }
   }
 }
 
-void ChromeContentRulesRegistry::Apply(
-    content::WebContents* contents,
-    const std::vector<std::string>& matching_css_selectors) {
-  matching_css_selectors_[contents] = matching_css_selectors;
+void ChromeContentRulesRegistry::RequestEvaluation(
+    content::WebContents* contents) {
+  EvaluateConditionsForTab(contents);
+}
 
-  EvaluateConditionsForTab(contents);
+bool ChromeContentRulesRegistry::ShouldManageConditionsForBrowserContext(
+    content::BrowserContext* context) {
+  return ManagingRulesForBrowserContext(context);
 }
 
 void ChromeContentRulesRegistry::DidNavigateMainFrame(
     content::WebContents* contents,
     const content::LoadCommittedDetails& details,
     const content::FrameNavigateParams& params) {
-  OnTabNavigation(contents, details.is_in_page);
+  if (ContainsKey(active_rules_, contents))
+    css_condition_tracker_.OnWebContentsNavigation(contents, details, params);
 }
 
 void ChromeContentRulesRegistry::DidNavigateMainFrameOfOriginalContext(
     content::WebContents* contents,
     const content::LoadCommittedDetails& details,
     const content::FrameNavigateParams& params) {
   DCHECK(browser_context()->IsOffTheRecord());
-  OnTabNavigation(contents, details.is_in_page);
+  if (ContainsKey(active_rules_, contents))
+    css_condition_tracker_.OnWebContentsNavigation(contents, details, params);
 }
 
-void ChromeContentRulesRegistry::OnTabNavigation(content::WebContents* tab,
-                                                 bool is_in_page_navigation) {
-  if (is_in_page_navigation) {
-    // Within-page navigations don't change the set of elements that
-    // exist, and we only support filtering on the top-level URL, so
-    // this can't change which rules match.
-    return;
-  }
-
-  // Top-level navigation produces a new document. Initially, the
-  // document's empty, so no CSS rules match.  The renderer will send
-  // an ExtensionHostMsg_OnWatchedPageChange later if any CSS rules
-  // match.
-  matching_css_selectors_[tab].clear();
-  EvaluateConditionsForTab(tab);
+void ChromeContentRulesRegistry::TrackRulesForWebContents(
+    content::WebContents* contents) {
+  // We rely on the_rules_ to have a key-value pair for |contents| to know which
+  // WebContents we are working with.
+  active_rules_[contents] = std::set<const ContentRule*>();
+  css_condition_tracker_.TrackForWebContents(contents);
 }
 
 bool ChromeContentRulesRegistry::ManagingRulesForBrowserContext(
     content::BrowserContext* context) {
   // Manage both the normal context and incognito contexts associated with it.
   return Profile::FromBrowserContext(context)->GetOriginalProfile() ==
       Profile::FromBrowserContext(browser_context());
 }
 
 std::set<const ContentRule*> ChromeContentRulesRegistry::GetMatches(
@@ skipping 92 matching lines @@
   // Register url patterns in url_matcher_.
   URLMatcherConditionSet::Vector all_new_condition_sets;
   for (const std::pair<ContentRule::GlobalRuleId,
                        linked_ptr<const ContentRule>>& rule_id_rule_pair :
        new_content_rules) {
     const linked_ptr<const ContentRule>& rule = rule_id_rule_pair.second;
     rule->conditions().GetURLMatcherConditionSets(&all_new_condition_sets);
   }
   url_matcher_.AddConditionSets(all_new_condition_sets);
 
-  UpdateConditionCache();
+  UpdateCssSelectorsFromRules();
   EvaluateConditionsForAllTabs();
 
   return std::string();
 }
 
 std::string ChromeContentRulesRegistry::RemoveRulesImpl(
     const std::string& extension_id,
     const std::vector<std::string>& rule_identifiers) {
   // URLMatcherConditionSet IDs that can be removed from URLMatcher.
   std::vector<URLMatcherConditionSet::ID> remove_from_url_matcher;
@@ skipping 26 matching lines @@
       }
     }
 
     // Remove reference to actual rule.
     content_rules_.erase(content_rules_entry);
   }
 
   // Clear URLMatcher based on condition_set_ids that are not needed any more.
   url_matcher_.RemoveConditionSets(remove_from_url_matcher);
 
-  UpdateConditionCache();
+  UpdateCssSelectorsFromRules();
 
   return std::string();
 }
 
 std::string ChromeContentRulesRegistry::RemoveAllRulesImpl(
     const std::string& extension_id) {
   // Search all identifiers of rules that belong to extension |extension_id|.
   std::vector<std::string> rule_identifiers;
   for (const std::pair<ContentRule::GlobalRuleId,
                        linked_ptr<const ContentRule>>& rule_id_rule_pair :
        content_rules_) {
     const ContentRule::GlobalRuleId& global_rule_id = rule_id_rule_pair.first;
     if (global_rule_id.first == extension_id)
       rule_identifiers.push_back(global_rule_id.second);
   }
 
   return RemoveRulesImpl(extension_id, rule_identifiers);
 }
 
-void ChromeContentRulesRegistry::UpdateConditionCache() {
+void ChromeContentRulesRegistry::UpdateCssSelectorsFromRules() {
   std::set<std::string> css_selectors;  // We rely on this being sorted.
   for (const std::pair<ContentRule::GlobalRuleId,
                        linked_ptr<const ContentRule>>& rule_id_rule_pair :
        content_rules_) {
     const ContentRule& rule = *rule_id_rule_pair.second;
     for (const linked_ptr<const ContentCondition>& condition :
          rule.conditions()) {
       const std::vector<std::string>& condition_css_selectors =
           condition->css_selectors();
       css_selectors.insert(condition_css_selectors.begin(),
                            condition_css_selectors.end());
     }
   }
 
-  if (css_selectors.size() != watched_css_selectors_.size() ||
-      !std::equal(css_selectors.begin(),
-                  css_selectors.end(),
-                  watched_css_selectors_.begin())) {
-    watched_css_selectors_.assign(css_selectors.begin(), css_selectors.end());
-
-    for (content::RenderProcessHost::iterator it(
-             content::RenderProcessHost::AllHostsIterator());
-         !it.IsAtEnd();
-         it.Advance()) {
-      content::RenderProcessHost* process = it.GetCurrentValue();
-      InstructRenderProcessIfSameBrowserContext(process);
-    }
-  }
-}
-
-void ChromeContentRulesRegistry::InstructRenderProcessIfSameBrowserContext(
-    content::RenderProcessHost* process) {
-  if (ManagingRulesForBrowserContext(process->GetBrowserContext()))
-    process->Send(new ExtensionMsg_WatchPages(watched_css_selectors_));
+  css_condition_tracker_.SetWatchedCssSelectors(css_selectors);
 }
 
 void ChromeContentRulesRegistry::EvaluateConditionsForTab(
     content::WebContents* tab) {
   extensions::RendererContentMatchData renderer_data;
   renderer_data.page_url_matches = url_matcher_.MatchURL(tab->GetURL());
-  renderer_data.css_selectors.insert(matching_css_selectors_[tab].begin(),
-                                     matching_css_selectors_[tab].end());
+  css_condition_tracker_.GetMatchingCssSelectors(tab,
+                                                 &renderer_data.css_selectors);
   std::set<const ContentRule*> matching_rules =
       GetMatches(renderer_data, tab->GetBrowserContext()->IsOffTheRecord());
   if (matching_rules.empty() && !ContainsKey(active_rules_, tab))
     return;
 
   std::set<const ContentRule*>& prev_matching_rules = active_rules_[tab];
   ContentAction::ApplyInfo apply_info = {browser_context(), tab};
   for (const ContentRule* rule : matching_rules) {
     apply_info.priority = rule->priority();
     if (!ContainsKey(prev_matching_rules, rule)) {
       rule->actions().Apply(rule->extension_id(), base::Time(), &apply_info);
     } else {
       rule->actions().Reapply(rule->extension_id(), base::Time(), &apply_info);
     }
   }
   for (const ContentRule* rule : prev_matching_rules) {
     if (!ContainsKey(matching_rules, rule)) {
       apply_info.priority = rule->priority();
       rule->actions().Revert(rule->extension_id(), base::Time(), &apply_info);
     }
   }
 
   if (matching_rules.empty())
-    active_rules_.erase(tab);
+    active_rules_[tab].clear();
   else
     swap(matching_rules, prev_matching_rules);
 }
 
 void ChromeContentRulesRegistry::EvaluateConditionsForAllTabs() {
-  for (chrome::BrowserIterator it; !it.done(); it.Next()) {
-    Browser* browser = *it;
-    if (!ManagingRulesForBrowserContext(browser->profile()))
-      continue;
-
-    for (int i = 0, tab_count = browser->tab_strip_model()->count();
-         i < tab_count;
-         ++i)
-      EvaluateConditionsForTab(browser->tab_strip_model()->GetWebContentsAt(i));
-  }
+  ForEachWebContents([this](content::WebContents* contents) {
+    EvaluateConditionsForTab(contents);
+  });
 }
 
 bool ChromeContentRulesRegistry::IsEmpty() const {
   return match_id_to_rule_.empty() && content_rules_.empty() &&
          url_matcher_.IsEmpty();
 }
 
+void ChromeContentRulesRegistry::UpdateMatchingCssSelectorsForTesting(
+    content::WebContents* contents,
+    const std::vector<std::string>& matching_css_selectors) {
+  css_condition_tracker_.UpdateMatchingCssSelectorsForTesting(
+      contents,
+      matching_css_selectors);
+}
+
+size_t ChromeContentRulesRegistry::GetActiveRulesCountForTesting() {
+  size_t count = 0;
+  for (auto web_contents_rules_pair : active_rules_)
+    count += web_contents_rules_pair.second.size();
+  return count;
+}
+
 ChromeContentRulesRegistry::~ChromeContentRulesRegistry() {
 }
 
 base::Time ChromeContentRulesRegistry::GetExtensionInstallationTime(
     const std::string& extension_id) const {
   if (!extension_info_map_.get())  // May be NULL during testing.
     return base::Time();
 
   return extension_info_map_->GetInstallTime(extension_id);
 }
 
 }  // namespace extensions