Removed unused network logging from extensions throttle.

The extensions network throttle (ExtensionThrottleManager) used
to use the net::NetLog to log throttling activity. Logging was
only done if ExtensionThrottleManager::set_net_log was called,
but that was removed nearly four years ago in refs/heads/master@{#298862}
(https://codereview.chromium.org/631203003).

This change removes the logging implementation as these classes
will soon be moving to the render process.

Bug: 784576
Change-Id: I1025dd6f3134d438e549165f5b7045b3ecf2dc61
Reviewed-on: https://chromium-review.googlesource.com/1113899
Commit-Queue: Chris Mumford <cmumford@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570096}

extensions/browser/extension_throttle_entry.cc

@@ -13,9 +13,6 @@
 #include "base/values.h"
 #include "extensions/browser/extension_throttle_manager.h"
 #include "net/base/load_flags.h"
-#include "net/log/net_log_capture_mode.h"
-#include "net/log/net_log_event_type.h"
-#include "net/log/net_log_source_type.h"
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_context.h"
 
@@ -47,20 +44,6 @@ const double ExtensionThrottleEntry::kDefaultJitterFactor = 0.4;
 const int ExtensionThrottleEntry::kDefaultMaximumBackoffMs = 15 * 60 * 1000;
 const int ExtensionThrottleEntry::kDefaultEntryLifetimeMs = 2 * 60 * 1000;
 
-// Returns NetLog parameters when a request is rejected by throttling.
-std::unique_ptr<base::Value> NetLogRejectedRequestCallback(
-    const std::string* url_id,
-    int num_failures,
-    const base::TimeDelta& release_after,
-    net::NetLogCaptureMode /* capture_mode */) {
-  std::unique_ptr<base::DictionaryValue> dict(new base::DictionaryValue());
-  dict->SetString("url", *url_id);
-  dict->SetInteger("num_failures", num_failures);
-  dict->SetInteger("release_after_ms",
-                   static_cast<int>(release_after.InMilliseconds()));
-  return std::move(dict);
-}
-
 ExtensionThrottleEntry::ExtensionThrottleEntry(
     ExtensionThrottleManager* manager,
     const std::string& url_id)
@@ -78,9 +61,6 @@ ExtensionThrottleEntry::ExtensionThrottleEntry(
       backoff_entry_(&backoff_policy_),
       manager_(manager),
       url_id_(url_id),
-      net_log_(net::NetLogWithSource::Make(
-          manager->net_log(),
-          net::NetLogSourceType::EXPONENTIAL_BACKOFF_THROTTLING)),
       ignore_user_gesture_load_flag_for_tests_(
           ignore_user_gesture_load_flag_for_tests) {
   DCHECK(manager_);
@@ -153,10 +133,6 @@ bool ExtensionThrottleEntry::ShouldRejectRequest(
   if (!is_backoff_disabled_ && (ignore_user_gesture_load_flag_for_tests_ ||
                                 !ExplicitUserRequest(request.load_flags())) &&
       GetBackoffEntry()->ShouldRejectRequest()) {
-    net_log_.AddEvent(net::NetLogEventType::THROTTLING_REJECTED_REQUEST,
-                      base::Bind(&NetLogRejectedRequestCallback, &url_id_,
-                                 GetBackoffEntry()->failure_count(),
-                                 GetBackoffEntry()->GetTimeUntilRelease()));
     reject_request = true;
   }
   return reject_request;

extensions/browser/extension_throttle_entry.h

@@ -14,7 +14,6 @@
 #include "base/time/time.h"
 #include "extensions/browser/extension_throttle_entry_interface.h"
 #include "net/base/backoff_entry.h"
-#include "net/log/net_log_with_source.h"
 
 namespace extensions {
 
@@ -155,7 +154,6 @@ class ExtensionThrottleEntry : public ExtensionThrottleEntryInterface {
   // Canonicalized URL string that this entry is for; used for logging only.
   std::string url_id_;
 
-  net::NetLogWithSource net_log_;
   bool ignore_user_gesture_load_flag_for_tests_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionThrottleEntry);

extensions/browser/extension_throttle_manager.cc

@@ -25,7 +25,6 @@ const unsigned int ExtensionThrottleManager::kRequestsBetweenCollecting = 200;
 
 ExtensionThrottleManager::ExtensionThrottleManager()
     : requests_since_last_gc_(0),
-      logged_for_localhost_disabled_(false),
       registered_from_thread_(base::kInvalidThreadId),
       ignore_user_gesture_load_flag_for_tests_(false) {
   url_id_replacements_.ClearPassword();
@@ -99,13 +98,6 @@ ExtensionThrottleManager::RegisterRequestUrl(const GURL& url) {
     // just constructed.  This is to allow unit tests to explicitly override
     // the entry for localhost URLs.
     if (net::IsLocalhost(url)) {
-      if (!logged_for_localhost_disabled_) {
-        logged_for_localhost_disabled_ = true;
-        std::string host = url.host();
-        net_log_.AddEvent(net::NetLogEventType::THROTTLING_DISABLED_FOR_HOST,
-                          net::NetLog::StringCallback("host", &host));
-      }
-
       // TODO(joi): Once sliding window is separate from back-off throttling,
       // we can simply return a dummy implementation of
       // ExtensionThrottleEntryInterface here that never blocks anything.
@@ -144,16 +136,6 @@ void ExtensionThrottleManager::SetIgnoreUserGestureLoadFlagForTests(
   ignore_user_gesture_load_flag_for_tests_ = true;
 }
 
-void ExtensionThrottleManager::set_net_log(net::NetLog* net_log) {
-  DCHECK(net_log);
-  net_log_ = net::NetLogWithSource::Make(
-      net_log, net::NetLogSourceType::EXPONENTIAL_BACKOFF_THROTTLING);
-}
-
-net::NetLog* ExtensionThrottleManager::net_log() const {
-  return net_log_.net_log();
-}
-
 void ExtensionThrottleManager::OnNetworkChanged(
     net::NetworkChangeNotifier::ConnectionType type) {
   // When we switch from online to offline or change IP addresses, we

extensions/browser/extension_throttle_manager.h

@@ -23,11 +23,6 @@ namespace content {
 class ResourceThrottle;
 }
 
-namespace net {
-class NetLog;
-class NetLogWithSource;
-}
-
 namespace extensions {
 
 // Class that registers URL request throttler entries for URLs being accessed
@@ -87,10 +82,6 @@ class ExtensionThrottleManager
   void set_enforce_throttling(bool enforce);
   bool enforce_throttling();
 
-  // Sets the net::NetLog instance to use.
-  void set_net_log(net::NetLog* net_log);
-  net::NetLog* net_log() const;
-
   // NetworkChangeObserver interface.
   void OnNetworkChanged(
       net::NetworkChangeNotifier::ConnectionType type) override;
@@ -135,13 +126,6 @@ class ExtensionThrottleManager
   // Valid after construction.
   GURL::Replacements url_id_replacements_;
 
-  // Initially false, switches to true once we have logged because of back-off
-  // being disabled for localhost.
-  bool logged_for_localhost_disabled_;
-
-  // net::NetLog to use, if configured.
-  net::NetLogWithSource net_log_;
-
   // Valid once we've registered for network notifications.
   base::PlatformThreadId registered_from_thread_;