Reland "Add NetLog events for cookie blocking by NetworkDelegate"

This is a reland of d184f073
The CL was speculatively reverted for an unrelated bug (876563)

TBR=mmenke@chromium.org

Original change's description:
> Add NetLog events for cookie blocking by NetworkDelegate
>
> Cookies setting and getting can be blocked by a NetworkDelegate.
> This CL adds NetLog events so they can aid in the investigation of cookies bugs.
>
> Bug: 875849
> Change-Id: Ia2a09b443fb1ebfe8ce9dde1617920264f6f24a7
> Reviewed-on: https://chromium-review.googlesource.com/1181244
> Reviewed-by: Matt Menke <mmenke@chromium.org>
> Commit-Queue: Helen Li <xunjieli@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#584809}

Bug: 875849
Change-Id: I19e285f078599084d53c9e68a8082ef43d86e067
Reviewed-on: https://chromium-review.googlesource.com/1185102Reviewed-by: Helen Li <xunjieli@chromium.org>
Commit-Queue: Helen Li <xunjieli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585049}

net/log/net_log_event_type_list.h

@@ -3165,3 +3165,13 @@ EVENT_TYPE(COOKIE_PERSISTENT_STORE_KEY_LOAD_COMPLETED)
 //    "type": <Classname of persistent cookie store>
 //  }
 EVENT_TYPE(COOKIE_PERSISTENT_STORE_CLOSED)
+
+// Event emitted when getting cookies is blocked by a NetworkDelegate.
+//  {
+//  }
+EVENT_TYPE(COOKIE_GET_BLOCKED_BY_NETWORK_DELEGATE)
+
+// Event emitted when setting cookies is blocked by a NetworkDelegate.
+//  {
+//  }
+EVENT_TYPE(COOKIE_SET_BLOCKED_BY_NETWORK_DELEGATE)

net/url_request/url_request.cc

@@ -1074,21 +1074,30 @@ void URLRequest::NotifySSLCertificateError(const SSLInfo& ssl_info,
 
 bool URLRequest::CanGetCookies(const CookieList& cookie_list) const {
   DCHECK(!(load_flags_ & LOAD_DO_NOT_SEND_COOKIES));
+  bool can_get_cookies = g_default_can_use_cookies;
   if (network_delegate_) {
-    return network_delegate_->CanGetCookies(*this, cookie_list,
-                                            /*allowed_from_caller=*/true);
+    can_get_cookies =
+        network_delegate_->CanGetCookies(*this, cookie_list,
+                                         /*allowed_from_caller=*/true);
   }
-  return g_default_can_use_cookies;
+
+  if (!can_get_cookies)
+    net_log_.AddEvent(NetLogEventType::COOKIE_GET_BLOCKED_BY_NETWORK_DELEGATE);
+  return can_get_cookies;
 }
 
 bool URLRequest::CanSetCookie(const net::CanonicalCookie& cookie,
                               CookieOptions* options) const {
   DCHECK(!(load_flags_ & LOAD_DO_NOT_SAVE_COOKIES));
+  bool can_set_cookies = g_default_can_use_cookies;
   if (network_delegate_) {
-    return network_delegate_->CanSetCookie(*this, cookie, options,
-                                           /*allowed_from_caller=*/true);
+    can_set_cookies =
+        network_delegate_->CanSetCookie(*this, cookie, options,
+                                        /*allowed_from_caller=*/true);
   }
-  return g_default_can_use_cookies;
+  if (!can_set_cookies)
+    net_log_.AddEvent(NetLogEventType::COOKIE_SET_BLOCKED_BY_NETWORK_DELEGATE);
+  return can_set_cookies;
 }
 
 bool URLRequest::CanEnablePrivacyMode() const {

net/url_request/url_request_unittest.cc

@@ -2740,6 +2740,12 @@ TEST_F(URLRequestTest, DoNotSendCookies_ViaPolicy) {
 
     EXPECT_EQ(0, network_delegate.blocked_get_cookies_count());
     EXPECT_EQ(0, network_delegate.blocked_set_cookie_count());
+    TestNetLogEntry::List entries;
+    net_log_.GetEntries(&entries);
+    for (const auto& entry : entries) {
+      EXPECT_NE(entry.type,
+                NetLogEventType::COOKIE_GET_BLOCKED_BY_NETWORK_DELEGATE);
+    }
   }
 
   // Verify that the cookie isn't sent.
@@ -2759,6 +2765,11 @@ TEST_F(URLRequestTest, DoNotSendCookies_ViaPolicy) {
 
     EXPECT_EQ(1, network_delegate.blocked_get_cookies_count());
     EXPECT_EQ(0, network_delegate.blocked_set_cookie_count());
+    TestNetLogEntry::List entries;
+    net_log_.GetEntries(&entries);
+    ExpectLogContainsSomewhereAfter(
+        entries, 0, NetLogEventType::COOKIE_GET_BLOCKED_BY_NETWORK_DELEGATE,
+        NetLogEventPhase::NONE);
   }
 }
 
@@ -2785,6 +2796,12 @@ TEST_F(URLRequestTest, DoNotSaveCookies_ViaPolicy) {
 
     EXPECT_EQ(0, network_delegate.blocked_get_cookies_count());
     EXPECT_EQ(0, network_delegate.blocked_set_cookie_count());
+    TestNetLogEntry::List entries;
+    net_log_.GetEntries(&entries);
+    for (const auto& entry : entries) {
+      EXPECT_NE(entry.type,
+                NetLogEventType::COOKIE_SET_BLOCKED_BY_NETWORK_DELEGATE);
+    }
   }
 
   // Try to set-up another cookie and update the previous cookie.
@@ -2802,6 +2819,11 @@ TEST_F(URLRequestTest, DoNotSaveCookies_ViaPolicy) {
 
     EXPECT_EQ(0, network_delegate.blocked_get_cookies_count());
     EXPECT_EQ(2, network_delegate.blocked_set_cookie_count());
+    TestNetLogEntry::List entries;
+    net_log_.GetEntries(&entries);
+    ExpectLogContainsSomewhereAfter(
+        entries, 0, NetLogEventType::COOKIE_SET_BLOCKED_BY_NETWORK_DELEGATE,
+        NetLogEventPhase::NONE);
   }
 
   // Verify the cookies weren't saved or updated.