[libwebm] Add export config (#42040)

ports/libwebm/fix-export-config.patch

@@ -0,0 +1,25 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index ebb3333..8fd53ef 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -459,13 +459,19 @@ endif()
+ # webm_parser headers are rooted at webm/.
+ set_target_properties(webm PROPERTIES PUBLIC_HEADER
+                                       "${webm_parser_public_headers}")
++set_target_properties(webm PROPERTIES EXPORT_NAME libwebm)
++target_include_directories(webm PUBLIC $<INSTALL_INTERFACE:include>)
+ install(
+-  TARGETS webm
++  TARGETS webm EXPORT unofficial-libwebm-targets
+   ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+   LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+   RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+   PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/webm)
+
++install(EXPORT unofficial-libwebm-targets
++        FILE unofficial-libwebm-config.cmake
++        NAMESPACE unofficial::libwebm::
++        DESTINATION share/unofficial-libwebm)
+ # Install common headers into a subdirectory to avoid breaking nested includes.
+ install(FILES ${libwebm_common_public_headers}
+         DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/webm/common)

ports/libwebm/portfile.cmake

@@ -6,6 +6,7 @@ vcpkg_from_github(
     HEAD_REF master
     PATCHES
         Fix-cmake.patch
+        fix-export-config.patch
 )
 
 vcpkg_cmake_configure(
@@ -21,7 +22,7 @@ vcpkg_cmake_configure(
 vcpkg_cmake_install()
 
 vcpkg_copy_pdbs()
-
+vcpkg_cmake_config_fixup(PACKAGE_NAME unofficial-libwebm)
 file(REMOVE_RECURSE "${CURRENT_PACKAGES_DIR}/debug/include")
 
 vcpkg_install_copyright(FILE_LIST "${SOURCE_PATH}/LICENSE.TXT")

ports/libwebm/vcpkg.json

@@ -1,6 +1,7 @@
 {
   "name": "libwebm",
   "version": "1.0.0.31",
+  "port-version": 1,
   "description": "WebM File Parser",
   "homepage": "https://github.com/webmproject/libwebm",
   "license": "BSD-3-Clause",

versions/baseline.json

@@ -5342,7 +5342,7 @@
     },
     "libwebm": {
       "baseline": "1.0.0.31",
-      "port-version": 0
+      "port-version": 1
     },
     "libwebp": {
       "baseline": "1.4.0",

versions/l-/libwebm.json

@@ -1,5 +1,10 @@
 {
   "versions": [
+    {
+      "git-tree": "1cfbac17267892f7a391ad56353f624a80451f88",
+      "version": "1.0.0.31",
+      "port-version": 1
+    },
     {
       "git-tree": "a1c52d996474cadfc08a913ec80155b1693c7af5",
       "version": "1.0.0.31",