Fully Qualify Microsoft::WRL::ComPtr in Comment

Response to
https://chromium-review.googlesource.com/c/chromium/src/+/722103/4/base/win/scoped_variant.h

BUG=

Change-Id: I5322c3f7295d50d657d2343a2ad45d7c767139b9
Reviewed-on: https://chromium-review.googlesource.com/723767
Commit-Queue: Robert Liao <robliao@chromium.org>
Commit-Queue: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#509473}

base/win/scoped_variant.h

@@ -125,8 +125,9 @@ class BASE_EXPORT ScopedVariant {
   // over that.
   const VARIANT* ptr() const { return &var_; }
 
-  // Like other scoped classes (e.g scoped_refptr, ComPtr, ScopedBstr)
-  // we support the assignment operator for the type we wrap.
+  // Like other scoped classes (e.g. scoped_refptr, ScopedBstr,
+  // Microsoft::WRL::ComPtr) we support the assignment operator for the type we
+  // wrap.
   ScopedVariant& operator=(const VARIANT& var);
 
   // A hack to pass a pointer to the variant where the accepting