GitLab

Create PDF placeholder in ChromeContentRendererClient when the
enable_plugins build flag is off. Tested manually on mobile.

Bug: 737787
Change-Id: Iddb276b8ce71c92ee7fb626115269f2730b8b943
Reviewed-on: https://chromium-review.googlesource.com/575190
Commit-Queue: Amber Won <amberwon@google.com>
Reviewed-by: Tommy Li <tommycli@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487561}