[DevTools] Fix line and column in CallstackSidebarPane for async frames

Since Runtime.CallFrame is 0-based, subtraction of 1 from line and column is redundant.

It was broken in: refs/heads/master@{#404923} (https://codereview.chromium.org/2145483002/).

BUG=591496
R=lushnikov@chromium.org

Review-Url: https://codereview.chromium.org/2153893002
Cr-Commit-Position: refs/heads/master@{#405831}
3 files changed