Deprecate use_thin_archive (#2694)

Thin archives are used on all platforms.

b/150410605

cobalt/site/docs/reference/starboard/gn-configuration.md

@@ -44,6 +44,5 @@ Book: /youtube/cobalt/_book.yaml
 | **`starboard_level_final_executable_type`**<br><br>The default value is `"executable"`. |
 | **`starboard_level_gtest_target_type`**<br><br>The default value is `"executable"`. |
 | **`static_library_configs`**<br><br> Target-specific configurations for static_library targets.<br><br>The default value is `[]`. |
-| **`use_thin_archive`**<br><br> Whether or not to link with thin archives.<br><br>The default value is `true`. |
 | **`v8_enable_pointer_compression_override`**<br><br> Set to true to enable pointer compression for v8.<br><br>The default value is `true`. |
 | **`v8_enable_webassembly`**<br><br> Enable WASM and install WebAssembly global.<br><br>The default value is `false`. |

starboard/build/config/BUILDCONFIG.gn

@@ -161,12 +161,9 @@ default_compiler_configs = [
   "//starboard/build/config:warnings_as_errors",
   "//starboard/build/config:default_compiler_flags",
   "//starboard/build/config:default_cpp_standard",
+  "//build/config/compiler:thin_archive",
 ]
 
-if (use_thin_archive) {
-  default_compiler_configs += [ "//build/config/compiler:thin_archive" ]
-}
-
 if (is_starboard) {
   default_compiler_configs += [ "//starboard/build/config:starboard" ]
 }

starboard/build/config/base_configuration.gni

@@ -149,9 +149,6 @@ declare_args() {
   # Set to true to enable pointer compression for v8.
   v8_enable_pointer_compression_override = true
 
-  # Whether or not to link with thin archives.
-  use_thin_archive = true
-
   # Whether or not to disable run-time type information (adding no_rtti flag).
   sb_use_no_rtti = false