Add new file option php_namespace. (#3162)

* Add new file option php_namespace.

Use this option to change the namespace of php generated classes.
Default is empty. When this option is empty, the package name will be
used for determining the namespace.

* Uncomment commented tests

* Revert gdb test change

* Update csharp descriptor.

* Add test for empty php_namespace.

1 files changed, 12 insertions, 0 deletions

diff --git a/php/src/Google/Protobuf/Internal/MethodDescriptorProto.php b/php/src/Google/Protobuf/Internal/MethodDescriptorProto.php
index 3d8df7af..c3f9f064 100644
--- a/php/src/Google/Protobuf/Internal/MethodDescriptorProto.php
+++ b/php/src/Google/Protobuf/Internal/MethodDescriptorProto.php
@@ -85,6 +85,8 @@ class MethodDescriptorProto extends \Google\Protobuf\Internal\Message
         GPBUtil::checkString($var, True);
         $this->name = $var;
         $this->has_name = true;
+
+        return $this;
     }
 
     public function hasName()
@@ -118,6 +120,8 @@ class MethodDescriptorProto extends \Google\Protobuf\Internal\Message
         GPBUtil::checkString($var, True);
         $this->input_type = $var;
         $this->has_input_type = true;
+
+        return $this;
     }
 
     public function hasInputType()
@@ -141,6 +145,8 @@ class MethodDescriptorProto extends \Google\Protobuf\Internal\Message
         GPBUtil::checkString($var, True);
         $this->output_type = $var;
         $this->has_output_type = true;
+
+        return $this;
     }
 
     public function hasOutputType()
@@ -164,6 +170,8 @@ class MethodDescriptorProto extends \Google\Protobuf\Internal\Message
         GPBUtil::checkMessage($var, \Google\Protobuf\Internal\MethodOptions::class);
         $this->options = $var;
         $this->has_options = true;
+
+        return $this;
     }
 
     public function hasOptions()
@@ -195,6 +203,8 @@ class MethodDescriptorProto extends \Google\Protobuf\Internal\Message
         GPBUtil::checkBool($var);
         $this->client_streaming = $var;
         $this->has_client_streaming = true;
+
+        return $this;
     }
 
     public function hasClientStreaming()
@@ -226,6 +236,8 @@ class MethodDescriptorProto extends \Google\Protobuf\Internal\Message
         GPBUtil::checkBool($var);
         $this->server_streaming = $var;
         $this->has_server_streaming = true;
+
+        return $this;
     }
 
     public function hasServerStreaming()