[Merge to 2623] Remove extra Release in pageCapture extension function implementation.

BUG=401364

Review URL: https://codereview.chromium.org/1761303003

Cr-Commit-Position: refs/heads/master@{#379361}
(cherry picked from commit 587ba472dfefe862855487c4e6faee859b686160)

Review URL: https://codereview.chromium.org/1776003003 .

Cr-Commit-Position: refs/branch-heads/2623@{#601}
Cr-Branched-From: 92d77538a86529ca35f9220bd3cd512cbea1f086-refs/heads/master@{#369907}
1 file changed