Support the Clear-Site-Data header on resource requests

content/browser/browsing_data/clear_site_data_throttle.cc

Index: content/browser/browsing_data/clear_site_data_throttle.cc
diff --git a/content/browser/browsing_data/clear_site_data_throttle.cc b/content/browser/browsing_data/clear_site_data_throttle.cc
index 9799e1c7a06cd8c6a5ab2d1a59d2472a7f47c40e..43127b3d14ad6db650c1622d78fe18a269e4d021 100644
--- a/content/browser/browsing_data/clear_site_data_throttle.cc
+++ b/content/browser/browsing_data/clear_site_data_throttle.cc
@@ -9,18 +9,25 @@
 #include "base/json/json_string_value_serializer.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
+#include "base/scoped_observer.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/values.h"
-#include "content/browser/frame_host/navigation_handle_impl.h"
+#include "content/browser/service_worker/service_worker_response_info.h"
 #include "content/public/browser/browser_context.h"
-#include "content/public/browser/content_browser_client.h"
-#include "content/public/browser/navigation_handle.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/browsing_data_filter_builder.h"
+#include "content/public/browser/browsing_data_remover.h"
+#include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
-#include "content/public/common/content_client.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/origin_util.h"
+#include "content/public/common/resource_response_info.h"
+#include "content/public/common/resource_type.h"
+#include "net/base/load_flags.h"
+#include "net/base/registry_controlled_domains/registry_controlled_domain.h"
 #include "net/http/http_response_headers.h"
+#include "net/url_request/redirect_info.h"
 #include "url/gurl.h"
 #include "url/origin.h"
 
@@ -28,29 +35,33 @@ namespace content {
 
 namespace {
 
-static const char* kClearSiteDataHeader = "Clear-Site-Data";
+const char kNameForLogging[] = "ClearSiteDataThrottle";
 
-static const char* kTypesKey = "types";
+const char kClearSiteDataHeader[] = "Clear-Site-Data";
+
+const char kTypesKey[] = "types";
+
+// Datatypes.
+const char kDatatypeCookies[] = "cookies";
+const char kDatatypeStorage[] = "storage";
+const char kDatatypeCache[] = "cache";
 
 // Pretty-printed log output.
-static const char* kConsoleMessagePrefix = "Clear-Site-Data header on '%s': %s";
-static const char* kClearingOneType = "Clearing %s.";
-static const char* kClearingTwoTypes = "Clearing %s and %s.";
-static const char* kClearingThreeTypes = "Clearing %s, %s, and %s.";
-
-// Console logging. Adds a |text| message with |level| to |messages|.
-void ConsoleLog(std::vector<ClearSiteDataThrottle::ConsoleMessage>* messages,
-                const GURL& url,
-                const std::string& text,
-                ConsoleMessageLevel level) {
-  messages->push_back({url, text, level});
-}
+const char kConsoleMessagePrefix[] = "Clear-Site-Data header on '%s': %s";

[mmenke, 2017/06/05 22:39:36]

nit:  Not actually a prefix

[msramek, 2017/06/06 18:20:57]

Done. Renamed to "template".

+const char kConsoleMessageCleared[] = "Cleared datatypes: %s.";
+const char kConsoleMessageDatatypeSeparator[] = ", ";
 
 bool AreExperimentalFeaturesEnabled() {
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kEnableExperimentalWebPlatformFeatures);
 }
 
+bool IsNavigationRequest(net::URLRequest* request) {
+  const ResourceRequestInfo* info = ResourceRequestInfo::ForRequest(request);
+  return info && (info->GetResourceType() == RESOURCE_TYPE_MAIN_FRAME ||
+                  info->GetResourceType() == RESOURCE_TYPE_SUB_FRAME);

[mmenke, 2017/06/05 22:39:36]

info && ResourceType::IsResourceTypeFrame(info->GetResourceType());?

[msramek, 2017/06/06 18:20:57]

Done. Good to know :)

+}
+
 // Represents the parameters as a single number to be recorded in a histogram.
 int ParametersMask(bool clear_cookies, bool clear_storage, bool clear_cache) {
   return static_cast<int>(clear_cookies) * (1 << 0) +
@@ -58,138 +69,398 @@ int ParametersMask(bool clear_cookies, bool clear_storage, bool clear_cache) {
          static_cast<int>(clear_cache) * (1 << 2);
 }
 
+// A helper function to pass an IO thread callback to a method called on
+// the UI thread.
+void JumpFromUIToIOThread(base::OnceClosure callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, std::move(callback));
+}
+
+// Finds the BrowserContext associated with the request and requests
+// the actual clearing of data for |origin|. The datatypes to be deleted

[mmenke, 2017/06/05 22:39:36]

nit:  data types

[msramek, 2017/06/06 18:20:57]

Done. Actually, we've been using "datatype" everywhere, and I always assumed
it's interchangeable, but Google suggests only "data type" as the correct
spelling.

+// are determined by |clear_cookies|, |clear_storage|, and |clear_cache|.
+// |web_contents_getter| identifies the WebContents from which the request
+// originated. Must be run on the UI thread. The |callback| will be executed
+// on the IO thread.
+class UIThreadSiteDataClearer : public BrowsingDataRemover::Observer {
+ public:
+  static void Run(
+      const ResourceRequestInfo::WebContentsGetter& web_contents_getter,
+      const url::Origin& origin,
+      bool clear_cookies,
+      bool clear_storage,
+      bool clear_cache,
+      base::OnceClosure callback) {
+    WebContents* web_contents = web_contents_getter.Run();
+    if (!web_contents)
+      return;
+
+    (new UIThreadSiteDataClearer(web_contents, origin, clear_cookies,
+                                 clear_storage, clear_cache,
+                                 std::move(callback)))
+        ->RunAndDestroySelfWhenDone();
+  }
+
+ private:
+  UIThreadSiteDataClearer(const WebContents* web_contents,
+                          const url::Origin& origin,
+                          bool clear_cookies,
+                          bool clear_storage,
+                          bool clear_cache,
+                          base::OnceClosure callback)
+      : origin_(origin),
+        clear_cookies_(clear_cookies),
+        clear_storage_(clear_storage),
+        clear_cache_(clear_cache),
+        callback_(std::move(callback)),
+        pending_task_count_(0),
+        remover_(nullptr),
+        scoped_observer_(this) {
+    DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+    remover_ = BrowserContext::GetBrowsingDataRemover(
+        web_contents->GetBrowserContext());
+    DCHECK(remover_);
+    scoped_observer_.Add(remover_);
+  }
+
+  ~UIThreadSiteDataClearer() override {}
+
+  void RunAndDestroySelfWhenDone() {
+    DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+    // Cookies and channel IDs are scoped to
+    // a) eTLD+1 of |origin|'s host if |origin|'s host is a registrable domain
+    //    or a subdomain thereof
+    // b) |origin|'s host exactly if it is an IP address or an internal hostname
+    //    (e.g. "localhost" or "fileserver").
+    // TODO(msramek): What about plugin data?
+    if (clear_cookies_) {
+      std::string domain = GetDomainAndRegistry(
+          origin_.host(),
+          net::registry_controlled_domains::INCLUDE_PRIVATE_REGISTRIES);
+
+      if (domain.empty())
+        domain = origin_.host();  // IP address or internal hostname.
+
+      std::unique_ptr<BrowsingDataFilterBuilder> domain_filter_builder(
+          BrowsingDataFilterBuilder::Create(
+              BrowsingDataFilterBuilder::WHITELIST));
+      domain_filter_builder->AddRegisterableDomain(domain);
+
+      pending_task_count_++;
+      remover_->RemoveWithFilterAndReply(
+          base::Time(), base::Time::Max(),
+          BrowsingDataRemover::DATA_TYPE_COOKIES |
+              BrowsingDataRemover::DATA_TYPE_CHANNEL_IDS,
+          BrowsingDataRemover::ORIGIN_TYPE_UNPROTECTED_WEB |
+              BrowsingDataRemover::ORIGIN_TYPE_PROTECTED_WEB,
+          std::move(domain_filter_builder), this);
+    }
+
+    // Delete origin-scoped data.
+    int remove_mask = 0;
+    if (clear_storage_)
+      remove_mask |= BrowsingDataRemover::DATA_TYPE_DOM_STORAGE;
+    if (clear_cache_)
+      remove_mask |= BrowsingDataRemover::DATA_TYPE_CACHE;
+
+    if (remove_mask) {
+      std::unique_ptr<BrowsingDataFilterBuilder> origin_filter_builder(
+          BrowsingDataFilterBuilder::Create(
+              BrowsingDataFilterBuilder::WHITELIST));
+      origin_filter_builder->AddOrigin(origin_);
+
+      pending_task_count_++;
+      remover_->RemoveWithFilterAndReply(
+          base::Time(), base::Time::Max(), remove_mask,
+          BrowsingDataRemover::ORIGIN_TYPE_UNPROTECTED_WEB |
+              BrowsingDataRemover::ORIGIN_TYPE_PROTECTED_WEB,
+          std::move(origin_filter_builder), this);
+    }

[mmenke, 2017/06/05 22:39:36]

DCHECK_GT(pending_task_count_, 0);

[msramek, 2017/06/06 18:20:57]

Done.

+  }
+
+  // BrowsingDataRemover::Observer;

[mmenke, 2017/06/05 22:39:36]

nit:  ; -> :  (At least I assume that was a typo)

[msramek, 2017/06/06 18:20:57]

Done. Yes :)

+  void OnBrowsingDataRemoverDone() override {
+    DCHECK(pending_task_count_);
+    if (--pending_task_count_)
+      return;
+
+    JumpFromUIToIOThread(std::move(callback_));
+    delete this;
+  }
+
+  url::Origin origin_;
+  bool clear_cookies_;
+  bool clear_storage_;
+  bool clear_cache_;
+  base::OnceClosure callback_;
+  int pending_task_count_;
+  BrowsingDataRemover* remover_;
+  ScopedObserver<BrowsingDataRemover, BrowsingDataRemover::Observer>
+      scoped_observer_;
+};
+
+// Outputs a single |formatted_message| on the UI thread.
+void OutputFormattedMessage(WebContents* web_contents,
+                            ConsoleMessageLevel level,
+                            const std::string& formatted_text) {
+  if (web_contents)
+    web_contents->GetMainFrame()->AddMessageToConsole(level, formatted_text);
+}
+
+// Outputs |messages| to the console of WebContents retrieved from
+// |web_contents_getter|. Must be run on the UI thread.
+void OutputMessagesOnUIThread(
+    const ResourceRequestInfo::WebContentsGetter& web_contents_getter,
+    const std::vector<ClearSiteDataThrottle::ConsoleMessagesDelegate::Message>&
+        messages,
+    const ClearSiteDataThrottle::ConsoleMessagesDelegate::
+        OutputFormattedMessageFunction& output_formatted_message_function) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  WebContents* web_contents = web_contents_getter.Run();
+
+  for (const auto& message : messages) {
+    // Prefix each message with |kConsoleMessagePrefix|.
+    output_formatted_message_function.Run(
+        web_contents, message.level,
+        base::StringPrintf(kConsoleMessagePrefix, message.url.spec().c_str(),
+                           message.text.c_str()));
+  }
+}
+
 }  // namespace
 
-// static
-std::unique_ptr<NavigationThrottle>
-ClearSiteDataThrottle::CreateThrottleForNavigation(NavigationHandle* handle) {
-  if (AreExperimentalFeaturesEnabled())
-    return base::WrapUnique(new ClearSiteDataThrottle(handle));
+////////////////////////////////////////////////////////////////////////////////
+// ConsoleMessagesDelegate
 
-  return std::unique_ptr<NavigationThrottle>();
+ClearSiteDataThrottle::ConsoleMessagesDelegate::ConsoleMessagesDelegate()
+    : output_formatted_message_function_(base::Bind(&OutputFormattedMessage)) {}
+
+ClearSiteDataThrottle::ConsoleMessagesDelegate::~ConsoleMessagesDelegate() {}
+
+void ClearSiteDataThrottle::ConsoleMessagesDelegate::AddMessage(
+    const GURL& url,
+    const std::string& text,
+    ConsoleMessageLevel level) {
+  messages_.push_back({url, text, level});
 }
 
-ClearSiteDataThrottle::ClearSiteDataThrottle(
-    NavigationHandle* navigation_handle)
-    : NavigationThrottle(navigation_handle),
-      clearing_in_progress_(false),
-      weak_ptr_factory_(this) {}
+void ClearSiteDataThrottle::ConsoleMessagesDelegate::OutputMessages(
+    const ResourceRequestInfo::WebContentsGetter& web_contents_getter) {
+  if (messages_.empty())
+    return;
+
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::BindOnce(&OutputMessagesOnUIThread, web_contents_getter,
+                     std::move(messages_), output_formatted_message_function_));
+
+  messages_.clear();
+}
+
+void ClearSiteDataThrottle::ConsoleMessagesDelegate::
+    SetOutputFormattedMessageFunctionForTesting(
+        const OutputFormattedMessageFunction& function) {
+  output_formatted_message_function_ = function;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// ClearSiteDataThrottle
+
+// static
+std::unique_ptr<ResourceThrottle>
+ClearSiteDataThrottle::MaybeCreateThrottleForRequest(net::URLRequest* request) {
+  // This is an experimental feature.
+  if (!AreExperimentalFeaturesEnabled())
+    return std::unique_ptr<ResourceThrottle>();

[mmenke, 2017/06/05 22:39:36]

While I'm sure this isn't exactly a huge consumer of resources, could we just do
this once, and stash its value in RDH?  We do similar things elsewhere to avoid
searching through the command line on a per-request basis.  Some code even
stashes values in globals to avoid it, but that seems icky.

[msramek, 2017/06/06 18:20:57]

Done. Sure, I was just trying to contain the knowledge of requirements for this
throttle in one file. If you're fine with adding it to RDH, we can do that too.

+
+  // The throttle has no purpose if the request has no ResourceRequestInfo,
+  // because we won't be able to determine whose data should be deleted.
+  if (!ResourceRequestInfo::ForRequest(request))
+    return std::unique_ptr<ResourceThrottle>();

[mmenke, 2017/06/05 22:42:36]

These two returns can just be "return nullptr;"

[msramek, 2017/06/06 18:20:57]

Done.

+
+  return base::WrapUnique(new ClearSiteDataThrottle(
+      request, base::MakeUnique<ConsoleMessagesDelegate>()));
+}
 
 ClearSiteDataThrottle::~ClearSiteDataThrottle() {
-  // At the end of the navigation we finally have access to the correct
-  // RenderFrameHost. Output the cached console messages. Prefix each sequence
-  // of messages belonging to the same URL with |kConsoleMessagePrefix|.
-  GURL last_seen_url;
-  for (const ConsoleMessage& message : messages_) {
-    if (message.url == last_seen_url) {
-      navigation_handle()->GetRenderFrameHost()->AddMessageToConsole(
-          message.level, message.text);
-    } else {
-      navigation_handle()->GetRenderFrameHost()->AddMessageToConsole(
-          message.level,
-          base::StringPrintf(kConsoleMessagePrefix, message.url.spec().c_str(),
-                             message.text.c_str()));
-    }
+  // Output the cached console messages. For navigations, we output console
+  // messages when the request is finished rather than in real time, since in
+  // the case of navigations swapping RenderFrameHost would cause the outputs
+  // to disappear.
+  if (IsNavigationRequest(request_))
+    OutputConsoleMessages();
+}
 
-    last_seen_url = message.url;
-  }
+const char* ClearSiteDataThrottle::GetNameForLogging() const {
+  return kNameForLogging;
+}
+
+void ClearSiteDataThrottle::WillRedirectRequest(
+    const net::RedirectInfo& redirect_info,
+    bool* defer) {
+  *defer = HandleHeader();
+
+  // For subresource requests, console messages are output on every redirect.
+  // If the redirect is deferred, wait until it is resumed.
+  if (!IsNavigationRequest(request_) && !*defer)
+    OutputConsoleMessages();
 }
 
-ClearSiteDataThrottle::ThrottleCheckResult
-ClearSiteDataThrottle::WillStartRequest() {
-  current_url_ = navigation_handle()->GetURL();
-  return PROCEED;
+void ClearSiteDataThrottle::WillProcessResponse(bool* defer) {
+  *defer = HandleHeader();
+
+  // For subresource requests, console messages are output on every redirect.
+  // If the redirect is deferred, wait until it is resumed.
+  if (!IsNavigationRequest(request_) && !*defer)
+    OutputConsoleMessages();
 }
 
-ClearSiteDataThrottle::ThrottleCheckResult
-ClearSiteDataThrottle::WillRedirectRequest() {
-  // We are processing a redirect from url1 to url2. GetResponseHeaders()
-  // contains headers from url1, but GetURL() is already equal to url2. Handle
-  // the headers before updating the URL, so that |current_url_| corresponds
-  // to the URL that sent the headers.
-  HandleHeader();
-  current_url_ = navigation_handle()->GetURL();
+// static
+bool ClearSiteDataThrottle::ParseHeaderForTesting(
+    const std::string& header,
+    bool* clear_cookies,
+    bool* clear_storage,
+    bool* clear_cache,
+    ConsoleMessagesDelegate* delegate,
+    const GURL& current_url) {
+  return ClearSiteDataThrottle::ParseHeader(
+      header, clear_cookies, clear_storage, clear_cache, delegate, current_url);
+}
 
-  return clearing_in_progress_ ? DEFER : PROCEED;
+ClearSiteDataThrottle::ClearSiteDataThrottle(
+    net::URLRequest* request,
+    std::unique_ptr<ConsoleMessagesDelegate> delegate)
+    : request_(request),
+      delegate_(std::move(delegate)),
+      weak_ptr_factory_(this) {
+  DCHECK(request_);
+  DCHECK(delegate_);
 }
 
-ClearSiteDataThrottle::ThrottleCheckResult
-ClearSiteDataThrottle::WillProcessResponse() {
-  HandleHeader();
-  return clearing_in_progress_ ? DEFER : PROCEED;
+const GURL& ClearSiteDataThrottle::GetCurrentURL() const {
+  return request_->url();
 }
 
-const char* ClearSiteDataThrottle::GetNameForLogging() {
-  return "ClearSiteDataThrottle";
+const net::HttpResponseHeaders* ClearSiteDataThrottle::GetResponseHeaders()
+    const {
+  return request_->response_headers();
 }
 
-void ClearSiteDataThrottle::HandleHeader() {
-  NavigationHandleImpl* handle =
-      static_cast<NavigationHandleImpl*>(navigation_handle());
-  const net::HttpResponseHeaders* headers = handle->GetResponseHeaders();
+bool ClearSiteDataThrottle::HandleHeader() {
+  const net::HttpResponseHeaders* headers = GetResponseHeaders();
 
-  if (!headers || !headers->HasHeader(kClearSiteDataHeader))
-    return;
+  std::string header_value;
+  if (!headers ||
+      !headers->GetNormalizedHeader(kClearSiteDataHeader, &header_value)) {
+    return false;
+  }
 
-  // Only accept the header on secure origins.
-  if (!IsOriginSecure(current_url_)) {
-    ConsoleLog(&messages_, current_url_, "Not supported for insecure origins.",
-               CONSOLE_MESSAGE_LEVEL_ERROR);
-    return;
+  // Only accept the header on secure non-unique origins.
+  if (!IsOriginSecure(GetCurrentURL())) {
+    delegate_->AddMessage(GetCurrentURL(),
+                          "Not supported for insecure origins.",
+                          CONSOLE_MESSAGE_LEVEL_ERROR);
+    return false;
   }
 
-  std::string header_value;
-  headers->GetNormalizedHeader(kClearSiteDataHeader, &header_value);
+  url::Origin origin(GetCurrentURL());
+  if (origin.unique()) {
+    delegate_->AddMessage(GetCurrentURL(), "Not supported for unique origins.",
+                          CONSOLE_MESSAGE_LEVEL_ERROR);
+    return false;
+  }
+
+  // The LOAD_DO_NOT_SAVE_COOKIES flag prohibits the request from doing any
+  // modification to cookies. Clear-Site-Data applies this restriction to other
+  // datatypes as well.
+  // TODO(msramek): Consider showing a blocked icon via
+  // TabSpecificContentSettings and reporting the action in the "Blocked"
+  // section of the cookies dialog in OIB.
+  if (request_->load_flags() & net::LOAD_DO_NOT_SAVE_COOKIES) {
+    delegate_->AddMessage(
+        GetCurrentURL(),
+        "The request's credentials mode prohibits modifying cookies "
+        "and other local data.",
+        CONSOLE_MESSAGE_LEVEL_ERROR);
+    return false;
+  }
+
+  // Service workers can handle fetches of third-party resources and inject
+  // arbitrary headers. Ignore responses that came from a service worker,
+  // as supporting Clear-Site-Data would give them the power to delete data from
+  // any website.
+  // See https://w3c.github.io/webappsec-clear-site-data/#service-workers
+  // for more information.
+  const ServiceWorkerResponseInfo* response_info =
+      ServiceWorkerResponseInfo::ForRequest(request_);
+  if (response_info) {
+    ResourceResponseInfo extra_response_info;
+    response_info->GetExtraResponseInfo(&extra_response_info);
+
+    if (extra_response_info.was_fetched_via_service_worker) {
+      delegate_->AddMessage(
+          GetCurrentURL(),
+          "Ignoring, as the response came from a service worker.",
+          CONSOLE_MESSAGE_LEVEL_ERROR);
+      return false;
+    }
+  }
 
   bool clear_cookies;
   bool clear_storage;
   bool clear_cache;
 
-  if (!ParseHeader(header_value, &clear_cookies, &clear_storage, &clear_cache,
-                   &messages_)) {
-    return;
+  if (!ClearSiteDataThrottle::ParseHeader(header_value, &clear_cookies,
+                                          &clear_storage, &clear_cache,
+                                          delegate_.get(), GetCurrentURL())) {
+    return false;
   }
 
+  // If the header is valid, clear the data for this browser context and origin.
+  clearing_started_ = base::TimeTicks::Now();
+
   // Record the call parameters.
   UMA_HISTOGRAM_ENUMERATION(
       "Navigation.ClearSiteData.Parameters",
       ParametersMask(clear_cookies, clear_storage, clear_cache), (1 << 3));
 
-  // If the header is valid, clear the data for this browser context and origin.
-  BrowserContext* browser_context =
-      navigation_handle()->GetWebContents()->GetBrowserContext();
-  url::Origin origin(current_url_);
+  base::WeakPtr<ClearSiteDataThrottle> weak_ptr =
+      weak_ptr_factory_.GetWeakPtr();
 
-  if (origin.unique()) {
-    ConsoleLog(&messages_, current_url_, "Not supported for unique origins.",
-               CONSOLE_MESSAGE_LEVEL_ERROR);
-    return;
-  }
+  // Immediately bind the weak pointer to the current thread (IO). This will
+  // make a potential misuse on the UI thread DCHECK immediately rather than
+  // later when it's correctly used on the IO thread again.
+  weak_ptr.get();
 
-  clearing_in_progress_ = true;
-  clearing_started_ = base::TimeTicks::Now();
-  GetContentClient()->browser()->ClearSiteData(
-      browser_context, origin, clear_cookies, clear_storage, clear_cache,
-      base::Bind(&ClearSiteDataThrottle::TaskFinished,
-                 weak_ptr_factory_.GetWeakPtr()));
+  ExecuteClearingTask(
+      origin, clear_cookies, clear_storage, clear_cache,
+      base::BindOnce(&ClearSiteDataThrottle::TaskFinished, weak_ptr));
+
+  return true;
 }
 
+// static
 bool ClearSiteDataThrottle::ParseHeader(const std::string& header,
                                         bool* clear_cookies,
                                         bool* clear_storage,
                                         bool* clear_cache,
-                                        std::vector<ConsoleMessage>* messages) {
+                                        ConsoleMessagesDelegate* delegate,
+                                        const GURL& current_url) {
   if (!base::IsStringASCII(header)) {
-    ConsoleLog(messages, current_url_, "Must only contain ASCII characters.",
-               CONSOLE_MESSAGE_LEVEL_ERROR);
+    delegate->AddMessage(current_url, "Must only contain ASCII characters.",
+                         CONSOLE_MESSAGE_LEVEL_ERROR);
     return false;
   }
 
   std::unique_ptr<base::Value> parsed_header = base::JSONReader::Read(header);
 
   if (!parsed_header) {
-    ConsoleLog(messages, current_url_, "Not a valid JSON.",
-               CONSOLE_MESSAGE_LEVEL_ERROR);
+    delegate->AddMessage(current_url, "Not a valid JSON.",

[mmenke, 2017/06/05 22:39:36]

"Not valid JSON."  or just "Invalid JSON." or, to match the next message
"Expecting valid JSON."

[msramek, 2017/06/06 18:20:57]

Done.

+                         CONSOLE_MESSAGE_LEVEL_ERROR);
     return false;
   }
 
@@ -197,9 +468,9 @@ bool ClearSiteDataThrottle::ParseHeader(const std::string& header,
   const base::ListValue* types = nullptr;
   if (!parsed_header->GetAsDictionary(&dictionary) ||
       !dictionary->GetListWithoutPathExpansion(kTypesKey, &types)) {
-    ConsoleLog(messages, current_url_,
-               "Expecting a JSON dictionary with a 'types' field.",
-               CONSOLE_MESSAGE_LEVEL_ERROR);
+    delegate->AddMessage(current_url,
+                         "Expecting a JSON dictionary with a 'types' field.",

[mmenke, 2017/06/05 22:39:36]

optional:  I think "Expected" may be a little more common for error messages?

[msramek, 2017/06/06 18:20:57]

Done. Yes, I just realized that when I was addressing the above comment :)

+                         CONSOLE_MESSAGE_LEVEL_ERROR);
     return false;
   }
 
@@ -209,78 +480,93 @@ bool ClearSiteDataThrottle::ParseHeader(const std::string& header,
   *clear_storage = false;
   *clear_cache = false;
 
-  std::vector<std::string> type_names;
+  std::string type_names;
   for (const base::Value& value : *types) {
     std::string type;
     value.GetAsString(&type);
 
     bool* datatype = nullptr;
 
-    if (type == "cookies") {
+    if (type == kDatatypeCookies) {
       datatype = clear_cookies;
-    } else if (type == "storage") {
+    } else if (type == kDatatypeStorage) {
       datatype = clear_storage;
-    } else if (type == "cache") {
+    } else if (type == kDatatypeCache) {
       datatype = clear_cache;
     } else {
       std::string serialized_type;
       JSONStringValueSerializer serializer(&serialized_type);
       serializer.Serialize(value);
-      ConsoleLog(
-          messages, current_url_,
-          base::StringPrintf("Invalid type: %s.", serialized_type.c_str()),
+      delegate->AddMessage(
+          current_url,
+          base::StringPrintf("Unrecognized type: %s.", serialized_type.c_str()),
           CONSOLE_MESSAGE_LEVEL_ERROR);
       continue;
     }
 
-    // Each data type should only be processed once.
     DCHECK(datatype);
+
+    // Each data type should only be processed once.
     if (*datatype)
       continue;
 
     *datatype = true;
-    type_names.push_back(type);
+    if (!type_names.empty())
+      type_names += kConsoleMessageDatatypeSeparator;
+    type_names += type;
   }
 
   if (!*clear_cookies && !*clear_storage && !*clear_cache) {
-    ConsoleLog(messages, current_url_,
-               "No valid types specified in the 'types' field.",
-               CONSOLE_MESSAGE_LEVEL_ERROR);
+    delegate->AddMessage(current_url,
+                         "No recognized types specified in the 'types' field.",
+                         CONSOLE_MESSAGE_LEVEL_ERROR);
     return false;
   }
 
   // Pretty-print which types are to be cleared.
-  std::string output;
-  switch (type_names.size()) {
-    case 1:
-      output = base::StringPrintf(kClearingOneType, type_names[0].c_str());
-      break;
-    case 2:
-      output = base::StringPrintf(kClearingTwoTypes, type_names[0].c_str(),
-                                  type_names[1].c_str());
-      break;
-    case 3:
-      output = base::StringPrintf(kClearingThreeTypes, type_names[0].c_str(),
-                                  type_names[1].c_str(), type_names[2].c_str());
-      break;
-    default:
-      NOTREACHED();
-  }
-  ConsoleLog(messages, current_url_, output, CONSOLE_MESSAGE_LEVEL_INFO);
+  delegate->AddMessage(
+      current_url,
+      base::StringPrintf(kConsoleMessageCleared, type_names.c_str()),
+      CONSOLE_MESSAGE_LEVEL_INFO);
 
   return true;
 }
 
+void ClearSiteDataThrottle::ExecuteClearingTask(const url::Origin& origin,
+                                                bool clear_cookies,
+                                                bool clear_storage,
+                                                bool clear_cache,
+                                                base::OnceClosure callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::BindOnce(&UIThreadSiteDataClearer::Run,
+                     ResourceRequestInfo::ForRequest(request_)
+                         ->GetWebContentsGetterForRequest(),
+                     origin, clear_cookies, clear_storage, clear_cache,
+                     std::move(callback)));
+}
+
 void ClearSiteDataThrottle::TaskFinished() {
-  DCHECK(clearing_in_progress_);
-  clearing_in_progress_ = false;
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DCHECK(!clearing_started_.is_null());
 
   UMA_HISTOGRAM_CUSTOM_TIMES("Navigation.ClearSiteData.Duration",
                              base::TimeTicks::Now() - clearing_started_,
                              base::TimeDelta::FromMilliseconds(1),
                              base::TimeDelta::FromSeconds(1), 50);
 
-  navigation_handle()->Resume();
+  // For subresource requests, console messages are output immediately.
+  if (!IsNavigationRequest(request_))
+    OutputConsoleMessages();

[mmenke, 2017/06/05 22:39:36]

optional:  Could make this into a utility function, since you duplicate it 3
times.  Don't see the logic changing much, but you never know.

[msramek, 2017/06/06 18:20:57]

OutputConsoleMessages() is called 4 times actually, 2 times with one condition
and 2 times with a slightly different one. I think handling the condition inside
the function and parameterizing the two cases would decrease readability here.

+
+  Resume();
+}
+
+void ClearSiteDataThrottle::OutputConsoleMessages() {
+  const ResourceRequestInfo* info = ResourceRequestInfo::ForRequest(request_);
+  if (info)
+    delegate_->OutputMessages(info->GetWebContentsGetterForRequest());
 }
 
 }  // namespace content