Remove remaining implicit scoped_ptr<T> to T* conversions in win8

GetArgumentsFromShortcut() introduced a new implicit conversion
since the last time the clang tool was run.
The other fix in MetroViewerProcessHost simply changes the
TaskRunner pointer to be passed as a scoped_refptr<T>, since it
takes a ref to the TaskRunner.

BUG=110610

Review URL: https://codereview.chromium.org/753743003

Cr-Commit-Position: refs/heads/master@{#305511}
3 files changed