[Merge to 2661] 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/1780813002 .

Cr-Commit-Position: refs/branch-heads/2661@{#159}
Cr-Branched-From: ef6f6ae5e4c96622286b563658d5cd62a6cf1197-refs/heads/master@{#378081}
1 file changed