GitLab

This CL makes following changes
- Uses default keyword for dtors in
ActionHandlingFakePepperPluginInstance, FakeRendererPpapiHost and
PdfAccessibilityTreeTest classes.
- Removes ConvertAXScrollToPdfScrollAlignment function from member
variable of PdfAxActionTarget to a function in anonymous namespace.
- Rephrased and moved comments in pdf_accessibility_tree_browsertest.cc
and accessibility_unittest.cc files.

Bug: 769940
Change-Id: If7515d09e271d867af72a2f74e10e43b10fff236
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1753370
Commit-Queue: Virender Singh <virens@microsoft.com>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Kevin Babbitt <kbabbitt@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#687314}