Platform: document why particular things aren't tested.

src/Magnum/Platform/Test/EmscriptenApplicationTest.cpp

@@ -170,10 +170,13 @@ EmscriptenApplicationTest::EmscriptenApplicationTest(const Arguments& arguments)
 
     Configuration conf;
     conf.setWindowFlags(Configuration::WindowFlag::Resizable);
+    GLConfiguration glConf;
     if(args.isSet("quiet"))
-        create(conf, GLConfiguration{}.addFlags(GLConfiguration::Flag::QuietLog));
-    else
-        create(conf);
+        glConf.addFlags(GLConfiguration::Flag::QuietLog);
+    /* No GL-specific verbose log in EmscriptenApplication that we'd need to
+       handle explicitly */
+    /* No GPU validation on WebGL */
+    create(conf, glConf);
 
     Debug{} << "window size" << windowSize()
         #ifdef MAGNUM_TARGET_GL

src/Magnum/Platform/Test/GlfwApplicationTest.cpp

@@ -131,6 +131,8 @@ GlfwApplicationTest::GlfwApplicationTest(const Arguments& arguments): Platform::
     GLConfiguration glConf;
     if(args.isSet("quiet"))
         glConf.addFlags(GLConfiguration::Flag::QuietLog);
+    /* No GL-specific verbose log in GlfwApplication that we'd need to handle
+       explicitly */
     if(args.isSet("gpu-validation"))
         glConf.addFlags(GLConfiguration::Flag::GpuValidation);
     create(conf, glConf);

src/Magnum/Platform/Test/Sdl2ApplicationTest.cpp

@@ -192,6 +192,8 @@ Sdl2ApplicationTest::Sdl2ApplicationTest(const Arguments& arguments): Platform::
     GLConfiguration glConf;
     if(args.isSet("quiet"))
         glConf.addFlags(GLConfiguration::Flag::QuietLog);
+    /* No GL-specific verbose log in Sdl2Application that we'd need to handle
+       explicitly */
     if(args.isSet("gpu-validation"))
         glConf.addFlags(GLConfiguration::Flag::GpuValidation);
     create(conf, glConf);

src/Magnum/Platform/Test/WindowlessCglApplicationTest.cpp

@@ -40,6 +40,7 @@ WindowlessCglApplicationTest::WindowlessCglApplicationTest(const Arguments& argu
         .addBooleanOption("quiet").setHelp("quiet", "like --magnum-log quiet, but specified via a Context::Configuration instead")
         .parse(arguments.argc, arguments.argv);
 
+    /* No verbose logs in the app, no GPU validation in CGL either */
     if(args.isSet("quiet"))
         createContext(Configuration{}.addFlags(Configuration::Flag::QuietLog));
     else

src/Magnum/Platform/Test/WindowlessGlxApplicationTest.cpp

@@ -44,6 +44,7 @@ WindowlessGlxApplicationTest::WindowlessGlxApplicationTest(const Arguments& argu
     Configuration conf;
     if(args.isSet("quiet"))
         conf.addFlags(Configuration::Flag::QuietLog);
+    /* No verbose logs in this app */
     if(args.isSet("gpu-validation"))
         conf.addFlags(Configuration::Flag::GpuValidation);
     createContext(conf);

src/Magnum/Platform/Test/WindowlessIosApplicationTest.cpp

@@ -40,6 +40,7 @@ WindowlessIosApplicationTest::WindowlessIosApplicationTest(const Arguments& argu
         .addBooleanOption("quiet").setHelp("quiet", "like --magnum-log quiet, but specified via a Context::Configuration instead")
         .parse(arguments.argc, arguments.argv);
 
+    /* No verbose logs in the app, no GPU validation in EAGL either */
     if(args.isSet("quiet"))
         createContext(Configuration{}.addFlags(Configuration::Flag::QuietLog));
     else