Implement GetSandboxType() on all platforms and implement for all process types.

content/browser/gpu/gpu_process_host.cc

Index: content/browser/gpu/gpu_process_host.cc
diff --git a/content/browser/gpu/gpu_process_host.cc b/content/browser/gpu/gpu_process_host.cc
index 64769850d66037004b082c05eac79709977422f2..1b83d868395c637b440dbdd39ae38f1f5343fbb7 100644
--- a/content/browser/gpu/gpu_process_host.cc
+++ b/content/browser/gpu/gpu_process_host.cc
@@ -35,6 +35,7 @@
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/result_codes.h"
+#include "content/public/common/sandbox_type.h"
 #include "content/public/common/sandboxed_process_launcher_delegate.h"
 #include "gpu/command_buffer/service/gpu_switches.h"
 #include "ipc/ipc_channel_handle.h"
@@ -264,6 +265,10 @@ class GpuSandboxedProcessLauncherDelegate
   base::ScopedFD TakeIpcFd() override { return ipc_fd_.Pass(); }
 #endif  // OS_WIN
 
+  SandboxType GetSandboxType() override {
+    return SANDBOX_TYPE_GPU;
+  }
+
  private:
 #if defined(OS_WIN)
   base::CommandLine* cmd_line_;