<webview>: Correctly shift focus between WebContents.

content/browser/web_contents/web_contents_impl.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 #define CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 
 #include <stdint.h>
 
 #include <functional>
@@ skipping 628 matching lines @@
   // void Paste() override;
   // void SelectAll() override;
   void MoveRangeSelectionExtent(const gfx::Point& extent) override;
   void SelectRange(const gfx::Point& base, const gfx::Point& extent) override;
   void AdjustSelectionByCharacterOffset(int start_adjust, int end_adjust)
       override;
   RenderWidgetHostInputEventRouter* GetInputEventRouter() override;
   void ReplicatePageFocus(bool is_focused) override;
   RenderWidgetHostImpl* GetFocusedRenderWidgetHost(
       RenderWidgetHostImpl* receiving_widget) override;
+  RenderWidgetHostImpl* GetRenderWidgetHostWithPageFocus() override;
+  void EnsureOwningContentsIsFocused(
+      RenderWidgetHostImpl* render_widget_host) override;
   void RendererUnresponsive(RenderWidgetHostImpl* render_widget_host,
                             RendererUnresponsiveType type) override;
   void RendererResponsive(RenderWidgetHostImpl* render_widget_host) override;
   void RequestToLockMouse(RenderWidgetHostImpl* render_widget_host,
                           bool user_gesture,
                           bool last_unlocked_by_target,
                           bool privileged) override;
   bool IsFullscreenForCurrentTab() const override;
   blink::WebDisplayMode GetDisplayMode(
       RenderWidgetHostImpl* render_widget_host) const override;
@@ skipping 342 matching lines @@
   // response. This won't actually update the throbber, but it will get picked
   // up at the next animation step if the throbber is going.
   void SetNotWaitingForResponse() { waiting_for_response_ = false; }
 
   // Returns the focused WebContents.
   // If there are multiple inner/outer WebContents (when embedding <webview>,
   // <guestview>, ...) returns the single one containing the currently focused
   // frame. Otherwise, returns this WebContents.
   WebContentsImpl* GetFocusedWebContents();
 
+  // Returns true if |this| is the focused WebContents or an ancestor of the
+  // focused WebContents.
+  bool ContainsOrIsFocusedWebContents();
+
   // Returns the root of the WebContents tree.
   WebContentsImpl* GetOutermostWebContents();
 
+  // Become the focused WebContentsImpl. This will activate this content's main
+  // frame RenderWidget and indirectly all its subframe widgets.
+  // GetFocusedRenderWidgetHost will search this WebContentsImpl for a focused
+  // RenderWidgetHost. The previously focused WebContentsImpl, if any, will have
+  // its RenderWidgetHosts deactivated.
+  void SetAsFocusedWebContentsIfNecessary();

[Charlie Reis, 2016/11/16 20:28:23]

This seems really subtle to me, and I'm concerned about landing a major change
to focus behavior just before branch.

It sounds like it affects how all tabs are focused.  Is it actually more
specific to webviews (i.e., inner WebContents)?  Is there a way to clarify if
so?

[avallee, 2016/11/16 21:18:10]

The concept of a "Focused" WebContents is for guest views, when there are
inner/outer WebContents. A single WebContents is focused and the normal routing
for keyboard input will search that WebContents for the focused frame/widget.

Updated comment.

[Charlie Reis, 2016/11/16 21:51:20]

Ok, I'm glad it's limited to that case.  I think it's worth clarifying this in
the code at some point, like having a section (similar to the "Navigation
helpers" one below) for focus that explains how this focus concept is different
from other places focus is handled.

[avallee, 2016/11/17 00:20:12]

Added comment header block.

+
   // Navigation helpers --------------------------------------------------------
   //
   // These functions are helpers for Navigate() and DidNavigate().
 
   // Handles post-navigation tasks in DidNavigate AFTER the entry has been
   // committed to the navigation controller. Note that the navigation entry is
   // not provided since it may be invalid/changed after being committed. The
   // current navigation entry is in the NavigationController at this point.
 
   // Helper for CreateNewWidget/CreateNewFullscreenWidget.
@@ skipping 433 matching lines @@
   // Adds/removes a callback called on creation of each new WebContents.
   static void AddCreatedCallbackForTesting(const CreatedCallback& callback);
   static void RemoveCreatedCallbackForTesting(const CreatedCallback& callback);
 
   DISALLOW_COPY_AND_ASSIGN(FriendZone);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_