Tool added to extract network traffic annotations.

tools/clang/traffic_annotation_extractor/tests/expected_outputs/______components_autofill_core_browser_payments_payments_client_cc(420).txt

+../../components/autofill/core/browser/payments/payments_client.cc
+autofill::payments::PaymentsClient::InitializeUrlFetcher
+420
+payments_sync_cards
+
+        semantics {
+          sender: "Payments"
+          description:
+            "This service communicates with Google Payments servers to upload "
+            "(save) or receive the user's credit card info."
+          trigger:
+            "Requests are triggered by a user action, such as selecting a "
+            "masked server card from Chromium's credit card autofill dropdown, "
+            "submitting a form which has credit card information, or accepting "
+            "the prompt to save a credit card to Payments servers."
+          data:
+            "In case of save, a protocol buffer containing relevant address "
+            "and credit card information which should be saved in Google "
+            "Payments servers, along with user credentials. In case of load, a "
+            "protocol buffer containing the id of the credit card to unmask, "
+            "an encrypted cvc value, an optional updated card expiration date, "
+            "and user credentials."
+          destination: GOOGLE_OWNED_SERVICE
+        }
+        policy {
+          cookies_allowed: false
+          setting:
+            "Users can enable or disable this feature in Chromium settings by "
+            "toggling 'Credit cards and addresses using Google Payments', "
+            "under 'Advanced sync settings...'. This feature is enabled by "
+            "default."
+          chrome_policy {
+            AutoFillEnabled {
+              policy_options {mode: MANDATORY}
+              AutoFillEnabled: false
+            }
+          }
+        }