Handshaker plugin mechanism.
diff --git a/vsprojects/vcxproj/grpc/grpc.vcxproj b/vsprojects/vcxproj/grpc/grpc.vcxproj
index 12535b2..2550d1e 100644
--- a/vsprojects/vcxproj/grpc/grpc.vcxproj
+++ b/vsprojects/vcxproj/grpc/grpc.vcxproj
@@ -306,6 +306,8 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\context.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\deadline_filter.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_factory.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_registry.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\http_client_filter.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\http_server_filter.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\message_size_filter.h" />
@@ -496,6 +498,10 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_factory.c">
+    </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_registry.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\http_client_filter.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\http_server_filter.c">
diff --git a/vsprojects/vcxproj/grpc/grpc.vcxproj.filters b/vsprojects/vcxproj/grpc/grpc.vcxproj.filters
index d5a8ac3..642ace6 100644
--- a/vsprojects/vcxproj/grpc/grpc.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc/grpc.vcxproj.filters
@@ -25,6 +25,12 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker.c">
       <Filter>src\core\lib\channel</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_factory.c">
+      <Filter>src\core\lib\channel</Filter>
+    </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_registry.c">
+      <Filter>src\core\lib\channel</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\http_client_filter.c">
       <Filter>src\core\lib\channel</Filter>
     </ClCompile>
@@ -761,6 +767,12 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker.h">
       <Filter>src\core\lib\channel</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_factory.h">
+      <Filter>src\core\lib\channel</Filter>
+    </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_registry.h">
+      <Filter>src\core\lib\channel</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\http_client_filter.h">
       <Filter>src\core\lib\channel</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj b/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj
index a37587c..15e3097 100644
--- a/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj
+++ b/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj
@@ -199,6 +199,8 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\context.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\deadline_filter.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_factory.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_registry.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\http_client_filter.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\http_server_filter.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\message_size_filter.h" />
@@ -345,6 +347,10 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_factory.c">
+    </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_registry.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\http_client_filter.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\http_server_filter.c">
diff --git a/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj.filters b/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj.filters
index 90c718f..43b7eaa 100644
--- a/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc_test_util/grpc_test_util.vcxproj.filters
@@ -82,6 +82,12 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker.c">
       <Filter>src\core\lib\channel</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_factory.c">
+      <Filter>src\core\lib\channel</Filter>
+    </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_registry.c">
+      <Filter>src\core\lib\channel</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\http_client_filter.c">
       <Filter>src\core\lib\channel</Filter>
     </ClCompile>
@@ -551,6 +557,12 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker.h">
       <Filter>src\core\lib\channel</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_factory.h">
+      <Filter>src\core\lib\channel</Filter>
+    </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_registry.h">
+      <Filter>src\core\lib\channel</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\http_client_filter.h">
       <Filter>src\core\lib\channel</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj
index 7eb562f..d1d3cb2 100644
--- a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj
+++ b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj
@@ -296,6 +296,8 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\context.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\deadline_filter.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_factory.h" />
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_registry.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\http_client_filter.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\http_server_filter.h" />
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\message_size_filter.h" />
@@ -464,6 +466,10 @@
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker.c">
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_factory.c">
+    </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_registry.c">
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\http_client_filter.c">
     </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\http_server_filter.c">
diff --git a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters
index 25295f7..7741c62 100644
--- a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters
@@ -28,6 +28,12 @@
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker.c">
       <Filter>src\core\lib\channel</Filter>
     </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_factory.c">
+      <Filter>src\core\lib\channel</Filter>
+    </ClCompile>
+    <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_registry.c">
+      <Filter>src\core\lib\channel</Filter>
+    </ClCompile>
     <ClCompile Include="$(SolutionDir)\..\src\core\lib\channel\http_client_filter.c">
       <Filter>src\core\lib\channel</Filter>
     </ClCompile>
@@ -674,6 +680,12 @@
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker.h">
       <Filter>src\core\lib\channel</Filter>
     </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_factory.h">
+      <Filter>src\core\lib\channel</Filter>
+    </ClInclude>
+    <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\handshaker_registry.h">
+      <Filter>src\core\lib\channel</Filter>
+    </ClInclude>
     <ClInclude Include="$(SolutionDir)\..\src\core\lib\channel\http_client_filter.h">
       <Filter>src\core\lib\channel</Filter>
     </ClInclude>