[on-hold][subresource_filter] Add ActivationTracker to track all activated contents

chrome/browser/subresource_filter/chrome_subresource_filter_client.h

Index: chrome/browser/subresource_filter/chrome_subresource_filter_client.h
diff --git a/chrome/browser/subresource_filter/chrome_subresource_filter_client.h b/chrome/browser/subresource_filter/chrome_subresource_filter_client.h
index 73649c90a5eb0030fb25cfa04a91aa07fa24d260..ab9d7d86b6aecfed029520c0d8e338d8abff964d 100644
--- a/chrome/browser/subresource_filter/chrome_subresource_filter_client.h
+++ b/chrome/browser/subresource_filter/chrome_subresource_filter_client.h
@@ -11,8 +11,10 @@
 #include "base/macros.h"
 #include "components/content_settings/core/common/content_settings.h"
 #include "components/subresource_filter/content/browser/subresource_filter_client.h"
+#include "content/public/browser/web_contents_observer.h"
 
 class GURL;
+class SubresourceFilterProfileContext;
 
 namespace content {
 class NavigationHandle;
@@ -62,7 +64,8 @@ enum SubresourceFilterAction {
 
 // Chrome implementation of SubresourceFilterClient.
 class ChromeSubresourceFilterClient
-    : public subresource_filter::SubresourceFilterClient {
+    : public subresource_filter::SubresourceFilterClient,
+      public content::WebContentsObserver {
  public:
   explicit ChromeSubresourceFilterClient(content::WebContents* web_contents);
   ~ChromeSubresourceFilterClient() override;
@@ -75,6 +78,8 @@ class ChromeSubresourceFilterClient
   void WhitelistInCurrentWebContents(const GURL& url) override;
   subresource_filter::VerifiedRulesetDealer::Handle* GetRulesetDealer()
       override;
+  void OnPageActivated(
+      const subresource_filter::ActivationState& state) override;
 
   bool did_show_ui_for_navigation() const {
     return did_show_ui_for_navigation_;
@@ -83,9 +88,17 @@ class ChromeSubresourceFilterClient
   static void LogAction(SubresourceFilterAction action);
 
  private:
+  // content::WebContentsObserver:
+  void DidStartNavigation(
+      content::NavigationHandle* navigation_handle) override;
+  void WebContentsDestroyed() override;
+
   ContentSetting GetContentSettingForUrl(const GURL& url);
   std::set<std::string> whitelisted_hosts_;
-  content::WebContents* web_contents_;
+
+  // Owned by the profile. Must outlive this class.
+  SubresourceFilterProfileContext* profile_context_;
+
   bool did_show_ui_for_navigation_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeSubresourceFilterClient);