GitLab

Original CL: http://crrev.com/c/2172854
Revert: http://crrev.com/c/2204841

The original CL got reverted because following browser test was failing
on the Mac10.12 tests bot -
PDFExtensionTest.PdfAccessibilityContextMenuAction

Added missing ContextMenuWaiter in the test to fix the issue.

Original description:
This CL adds support for invoking context menu on PDF via AT clients. To
show context menu for PDF plugin, the context menu action can be invoked
on respective EMBED node. This internally takes care of showing plugin
related context menu option(See ContextMenuController::ShowContextMenu()
for reference).

Implemented PdfAXActionTarget::ShowContextMenu() that forwards the call
to RenderAccessibilityImpl::ShowPluginContextMenu() to find the EMBED
object in accessibility tree and invoke ShowContextMenu() on EMBED node.

This CL also includes browser test to validate E2E scenario.

CQ_INCLUDE_TRYBOTS=luci.chromium.try:mac_chromium_dbg_ng

Bug: 1023283
Change-Id: Ie710fd24232b8dfeb3ce4bc6c0b56250ec9fbf0d

Tbr: dmazzoni@chromium.org,jochen@chromium.org
Change-Id: Ie710fd24232b8dfeb3ce4bc6c0b56250ec9fbf0d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2210080
Commit-Queue: Mansi Awasthi <maawas@microsoft.com>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Ankit Kumar 🌪️ <ankk@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#771188}