Merge to M52: Ensure LegacyRenderWidgetHostHWND is always created.

Merge to M52: Ensure LegacyRenderWidgetHostHWND is always created.

Previously, LegacyRenderWidgetHostHWND was only created inside
RenderWidgetHostViewAura::InternalSetBounds, and only if the parent
HWND was known. However, under some circumstances, InternalSetBounds
only gets called once and it gets called *before* the aura Window is
attached, so the legacy win never gets created.

Fix it by also trying to create the legacy win in
RWHVA::AddedToRootWindow().

BUG=613336
Review-Url: https://codereview.chromium.org/1996163002
Cr-Commit-Position: refs/heads/master@{#395649}
(cherry picked from commit a7e78f6f5d453c52313b74de10c5f680aa3d5ee3)

Committed: https://chromium.googlesource.com/chromium/src/+/686c6734e8d7b277dc252be0b209ecc24b9a46e2

[dmazzoni, 2016-05-25 22:12:31]

Description was changed from

==========
Merge to M52: Ensure LegacyRenderWidgetHostHWND is always created.

Previously, LegacyRenderWidgetHostHWND was only created inside
RenderWidgetHostViewAura::InternalSetBounds, and only if the parent
HWND was known. However, under some circumstances, InternalSetBounds
only gets called once and it gets called *before* the aura Window is
attached, so the legacy win never gets created.

Fix it by also trying to create the legacy win in
RWHVA::AddedToRootWindow().

BUG=613336

Review-Url: https://codereview.chromium.org/1996163002
Cr-Commit-Position: refs/heads/master@{#395649}
(cherry picked from commit a7e78f6f5d453c52313b74de10c5f680aa3d5ee3)
==========

to

==========
Merge to M52: Ensure LegacyRenderWidgetHostHWND is always created.

Previously, LegacyRenderWidgetHostHWND was only created inside
RenderWidgetHostViewAura::InternalSetBounds, and only if the parent
HWND was known. However, under some circumstances, InternalSetBounds
only gets called once and it gets called *before* the aura Window is
attached, so the legacy win never gets created.

Fix it by also trying to create the legacy win in
RWHVA::AddedToRootWindow().

BUG=613336

Review-Url: https://codereview.chromium.org/1996163002
Cr-Commit-Position: refs/heads/master@{#395649}
(cherry picked from commit a7e78f6f5d453c52313b74de10c5f680aa3d5ee3)

Committed:
https://chromium.googlesource.com/chromium/src/+/686c6734e8d7b277dc252be0b209...
==========

[dmazzoni, 2016-05-25 22:12:33]

Committed patchset #1 (id:1) manually as
686c6734e8d7b277dc252be0b209ecc24b9a46e2.