fix: Modify synth.py to update grpc transport options

.flake8

@@ -26,6 +26,7 @@ exclude =
   *_pb2.py
 
   # Standard linting exemptions.
+  **/.nox/**
   __pycache__,
   .git,
   *.pyc,

.pre-commit-config.yaml

@@ -2,7 +2,7 @@
 # See https://pre-commit.com/hooks.html for more hooks
 repos:
 -   repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v3.3.0
+    rev: v3.4.0
     hooks:
     -   id: trailing-whitespace
     -   id: end-of-file-fixer

CONTRIBUTING.rst

@@ -21,8 +21,8 @@ In order to add a feature:
 - The feature must be documented in both the API and narrative
   documentation.
 
-- The feature must work fully on the following CPython versions:  2.7,
-  3.5, 3.6, 3.7 and 3.8 on both UNIX and Windows.
+- The feature must work fully on the following CPython versions:
+  3.6, 3.7, 3.8 and 3.9 on both UNIX and Windows.
 
 - The feature must not add unnecessary dependencies (where
   "unnecessary" is of course subjective, but new dependencies should
@@ -202,25 +202,24 @@ Supported Python Versions
 
 We support:
 
--  `Python 3.5`_
 -  `Python 3.6`_
 -  `Python 3.7`_
 -  `Python 3.8`_
+-  `Python 3.9`_
 
-.. _Python 3.5: https://docs.python.org/3.5/
 .. _Python 3.6: https://docs.python.org/3.6/
 .. _Python 3.7: https://docs.python.org/3.7/
 .. _Python 3.8: https://docs.python.org/3.8/
+.. _Python 3.9: https://docs.python.org/3.9/
 
 
 Supported versions can be found in our ``noxfile.py`` `config`_.
 
 .. _config: https://github.com/googleapis/python-pubsub/blob/master/noxfile.py
 
-Python 2.7 support is deprecated. All code changes should maintain Python 2.7 compatibility until January 1, 2020.
 
 We also explicitly decided to support Python 3 beginning with version
-3.5. Reasons for this include:
+3.6. Reasons for this include:
 
 -  Encouraging use of newest versions of Python 3
 -  Taking the lead of `prominent`_ open-source `projects`_

google/cloud/pubsub_v1/proto/pubsub.proto

@@ -24,6 +24,7 @@ import "google/protobuf/duration.proto";
 import "google/protobuf/empty.proto";
 import "google/protobuf/field_mask.proto";
 import "google/protobuf/timestamp.proto";
+import "google/pubsub/v1/schema.proto";
 
 option cc_enable_arenas = true;
 option csharp_namespace = "Google.Cloud.PubSub.V1";
@@ -42,8 +43,8 @@ service Publisher {
       "https://www.googleapis.com/auth/cloud-platform,"
       "https://www.googleapis.com/auth/pubsub";
 
-  // Creates the given topic with the given name. See the [resource name rules](
-  // https://cloud.google.com/pubsub/docs/admin#resource_names).
+  // Creates the given topic with the given name. See the [resource name rules]
+  // (https://cloud.google.com/pubsub/docs/admin#resource_names).
   rpc CreateTopic(Topic) returns (Topic) {
     option (google.api.http) = {
       put: "/v1/{name=projects/*/topics/*}"
@@ -143,6 +144,21 @@ message MessageStoragePolicy {
   repeated string allowed_persistence_regions = 1;
 }
 
+// Settings for validating messages published against a schema.
+message SchemaSettings {
+  // Required. The name of the schema that messages published should be
+  // validated against. Format is `projects/{project}/schemas/{schema}`. The
+  // value of this field will be `_deleted-schema_` if the schema has been
+  // deleted.
+  string schema = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = { type: "pubsub.googleapis.com/Schema" }
+  ];
+
+  // The encoding of messages validated against `schema`.
+  Encoding encoding = 2;
+}
+
 // A topic resource.
 message Topic {
   option (google.api.resource) = {
@@ -173,6 +189,15 @@ message Topic {
   //
   // The expected format is `projects/*/locations/*/keyRings/*/cryptoKeys/*`.
   string kms_key_name = 5;
+
+  // Settings for validating messages published against a schema.
+  //
+  // EXPERIMENTAL: Schema support is in development and may not work yet.
+  SchemaSettings schema_settings = 6;
+
+  // Reserved for future use. This field is set only in responses from the
+  // server; it is ignored if it is set in any requests.
+  bool satisfies_pzs = 7;
 }
 
 // A message that is published by publishers and consumed by subscribers. The
@@ -587,8 +612,8 @@ service Subscriber {
   }
 
   // Seeks an existing subscription to a point in time or to a given snapshot,
-  // whichever is provided in the request. Snapshots are used in [Seek](
-  // https://cloud.google.com/pubsub/docs/replay-overview) operations, which
+  // whichever is provided in the request. Snapshots are used in [Seek]
+  // (https://cloud.google.com/pubsub/docs/replay-overview) operations, which
   // allow you to manage message acknowledgments in bulk. That is, you can set
   // the acknowledgment state of messages in an existing subscription to the
   // state captured by a snapshot. Note that both the subscription and the