<webview>: Correctly shift focus between WebContents.

content/browser/web_contents/web_contents_impl.h

Index: content/browser/web_contents/web_contents_impl.h
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index 358b8a6a0fa128ed851d627de3f369fea5733421..1d683c00fc06fee470e8e15441f83d8e538989c9 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -646,6 +646,9 @@ class CONTENT_EXPORT WebContentsImpl
   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;
@@ -1008,9 +1011,20 @@ class CONTENT_EXPORT WebContentsImpl
   // 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().