Use logging:stdio in preference to platform backend for tests and chi…

…p-tool

build/chip/chip_test_suite.gni

@@ -89,21 +89,16 @@ template("chip_test_suite") {
     forward_variables_from(invoker, "*", [ "tests" ])
 
     output_dir = "${root_out_dir}/lib"
+    public_deps = []  # invoker.public_deps will be appended below
 
-    if (!defined(invoker.public_deps)) {
-      public_deps = []
-    }
-
-    # TODO: figure out a way to auto-define dependency on stdio logging.
-    #       This dep is required since libSupportLayer now does not include
-    #       a default implementation.
-    #
-    #       Tests such as TestInetEndPoint need to exercise the system event
-    #       loop however they do not seem to include a logging binding so this
-    #       is forcefully added here.
+    # Prepend a dependency on logging:stdio so it is used in preference to the normal platform logging backend
     if (current_os != "zephyr" && current_os != "mbed") {
       public_deps += [ "${chip_root}/src/platform/logging:stdio" ]
     }
+
+    if (defined(invoker.public_deps)) {
+      public_deps += invoker.public_deps
+    }
   }
 
   if (chip_link_tests) {

examples/chip-tool/BUILD.gn

@@ -120,7 +120,9 @@ static_library("chip-tool-utils") {
 executable("chip-tool") {
   sources = [ "main.cpp" ]
 
-  deps = [ ":chip-tool-utils" ]
+  # Use stdio logging in preference to the platform backend
+  deps = [ "${chip_root}/src/platform/logging:stdio" ]
+  deps += [ ":chip-tool-utils" ]
 
   output_dir = root_out_dir
 }