libvpx: Add VP9 decoder.

source/libvpx/build/make/Makefile

Index: source/libvpx/build/make/Makefile
===================================================================
--- source/libvpx/build/make/Makefile	(revision 172621)
+++ source/libvpx/build/make/Makefile	(working copy)
@@ -253,10 +253,25 @@
 	$(if $(quiet),@echo "    [LD] $$@")
 	$(qexec)$$(LD) -shared $$(LDFLAGS) \
             -Wl,--no-undefined -Wl,-soname,$$(SONAME) \
-            -Wl,--version-script,$$(SO_VERSION_SCRIPT) -o $$@ \
-            $$(filter %.o,$$?) $$(extralibs)
+            -Wl,--version-script,$$(EXPORTS_FILE) -o $$@ \
+            $$(filter %.o,$$^) $$(extralibs)
 endef
 
+define dl_template
+# Not using a pattern rule here because we don't want to generate empty
+# archives when they are listed as a dependency in files not responsible
+# for creating them.
+$(1):
+	$(if $(quiet),@echo "    [LD] $$@")
+	$(qexec)$$(LD) -dynamiclib $$(LDFLAGS) \
+	    -exported_symbols_list $$(EXPORTS_FILE) \
+        -Wl,-headerpad_max_install_names,-compatibility_version,1.0,-current_version,$$(VERSION_MAJOR) \
+        -o $$@ \
+        $$(filter %.o,$$^) $$(extralibs)
+endef
+
+
+
 define lipo_lib_template
 $(1): $(addsuffix /$(1),$(FAT_ARCHS))
 	$(if $(quiet),@echo "    [LIPO] $$@")
@@ -321,6 +336,7 @@
 	@touch $@
 $(foreach lib,$(filter %_g.a,$(LIBS)),$(eval $(call archive_template,$(lib))))
 $(foreach lib,$(filter %so.$(VERSION_MAJOR).$(VERSION_MINOR).$(VERSION_PATCH),$(LIBS)),$(eval $(call so_template,$(lib))))
+$(foreach lib,$(filter %$(VERSION_MAJOR).dylib,$(LIBS)),$(eval $(call dl_template,$(lib))))
 
 INSTALL-LIBS=$(call cond_enabled,CONFIG_INSTALL_LIBS,INSTALL-LIBS)
 ifeq ($(MAKECMDGOALS),dist)