Switch RenderViewContextMenu to use RequestOpenURL

Currently, RenderViewContextMenu calls OpenURL on the source WebContents
when "open link in new tab" is activated. This is almost identical to
RequestOpenURL, except that it doesn't notify WebContentsObservers. This
change:

Changes NavigatorDelegate's RequestOpenURL to OpenURL, with a signature
identical to PageNavigator's OpenURL
Adds source_render_frame_host_id and source_render_process_id to OpenURLParams
Populates the above ids in NavigatorImpl's RequestOpenURL
Populates the above ids in RenderViewContextMenu's call to OpenURL
Removes RenderViewContextMenu's NotifyURLOpened

BUG=688214
R=nasko@chromium.org, creis@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/2666193002
Cr-Commit-Position: refs/heads/master@{#452151}
16 files changed