Remove a bunch of TOOLKIT_GTK in content/ and gpu/, as well as NPAPI plugins on linux

gpu/command_buffer/tests/gl_tests_main.cc

Index: gpu/command_buffer/tests/gl_tests_main.cc
diff --git a/gpu/command_buffer/tests/gl_tests_main.cc b/gpu/command_buffer/tests/gl_tests_main.cc
index 4a689a221fa6eb6a936f9bf8ff886d8e47e9afa6..460ecae94ecb1a57d45c798c619d2fd953c3fd22 100644
--- a/gpu/command_buffer/tests/gl_tests_main.cc
+++ b/gpu/command_buffer/tests/gl_tests_main.cc
@@ -18,10 +18,6 @@
 #include "ui/gl/android/gl_jni_registrar.h"
 #endif
 
-#if defined(TOOLKIT_GTK)
-#include "ui/gfx/gtk_util.h"
-#endif
-
 int main(int argc, char** argv) {
 #if defined(OS_ANDROID)
   ui::gl::android::RegisterJni(base::android::AttachCurrentThread());
@@ -32,9 +28,6 @@ int main(int argc, char** argv) {
 #if defined(OS_MACOSX)
   base::mac::ScopedNSAutoreleasePool pool;
 #endif
-#if defined(TOOLKIT_GTK)
-    gfx::GtkInitFromCommandLine(*CommandLine::ForCurrentProcess());
-#endif
   gfx::GLSurface::InitializeOneOff();
   ::gles2::Initialize();
   gpu::ApplyGpuDriverBugWorkarounds(CommandLine::ForCurrentProcess());