[WebRTC] Add ScreenCapturerDifferWrapper to share Differ across ScreenCapturers

webrtc/modules/desktop_capture/BUILD.gn

Index: webrtc/modules/desktop_capture/BUILD.gn
diff --git a/webrtc/modules/desktop_capture/BUILD.gn b/webrtc/modules/desktop_capture/BUILD.gn
index 61a3de2fe16379bccc07d2dd054fb62087e39dd2..982ac0f7069c8bf75544aa2577e3bfa474609ea3 100644
--- a/webrtc/modules/desktop_capture/BUILD.gn
+++ b/webrtc/modules/desktop_capture/BUILD.gn
@@ -130,6 +130,8 @@ source_set("desktop_capture") {
       "differ.h",
       "differ_block.cc",
       "differ_block.h",
+      "screen_capturer_differ_wrapper.cc",
+      "screen_capturer_differ_wrapper.h",
     ]
   }
 
@@ -174,8 +176,8 @@ if (use_desktop_capture_differ_sse2) {
   source_set("desktop_capture_differ_sse2") {
     visibility = [ ":*" ]
     sources = [
-      "differ_block_sse2.cc",
-      "differ_block_sse2.h",
+      "differ_vector_sse2.cc",
+      "differ_vector_sse2.h",
     ]
 
     configs += [ "../..:common_config" ]