Local changes:

1. ARM64 support build for Visual Studio.

diff --git a/third_party/webrtc/src/webrtc/typedefs.h b/third_party/webrtc/src/webrtc/typedefs.h
index 3034c7e74..9385befc9 100644
--- a/third_party/webrtc/src/webrtc/typedefs.h
+++ b/third_party/webrtc/src/webrtc/typedefs.h
@@ -23,7 +23,7 @@
 #define WEBRTC_ARCH_X86_64
 #define WEBRTC_ARCH_64_BITS
 #define WEBRTC_ARCH_LITTLE_ENDIAN
-#elif defined(__aarch64__)
+#elif defined(__aarch64__) || defined(_M_ARM64)
 #define WEBRTC_ARCH_64_BITS
 #define WEBRTC_ARCH_LITTLE_ENDIAN
 #elif defined(_M_IX86) || defined(__i386__)


2. Add include pj_config.h for PJSIP specific settings.

diff --git a/third_party/webrtc/src/webrtc/typedefs.h b/third_party/webrtc/src/webrtc/typedefs.h
index 9385befc9..3460ec880 100644
--- a/third_party/webrtc/src/webrtc/typedefs.h
+++ b/third_party/webrtc/src/webrtc/typedefs.h
@@ -14,6 +14,8 @@
 #ifndef WEBRTC_TYPEDEFS_H_
 #define WEBRTC_TYPEDEFS_H_

+#include "pj_config.h"
+
 // Processor architecture detection.  For more info on what's defined, see:
 //   http://msdn.microsoft.com/en-us/library/b0084kay.aspx
 //   http://www.agner.org/optimize/calling_conventions.pdf


3. Add support for RISC-V

diff --git a/third_party/webrtc/src/webrtc/typedefs.h b/third_party/webrtc/src/webrtc/typedefs.h
index 9385befc96..308f5fe982 100644
--- a/third_party/webrtc/src/webrtc/typedefs.h
+++ b/third_party/webrtc/src/webrtc/typedefs.h
@@ -47,6 +47,13 @@
 #elif defined(__pnacl__)
 #define WEBRTC_ARCH_32_BITS
 #define WEBRTC_ARCH_LITTLE_ENDIAN
+#elif defined(__riscv) || defined(__riscv__)
+#define WEBRTC_ARCH_LITTLE_ENDIAN
+#if __riscv_xlen == 64
+#define WEBRTC_ARCH_64_BITS
+#else
+#define WEBRTC_ARCH_32_BITS
+#endif
 #else
 #error Please add support for your architecture in typedefs.h
 #endif