Disable zoom-in and zoom-out buttons in toolbar menu for a crashed page.

chrome/browser/ui/browser_commands.h

Index: chrome/browser/ui/browser_commands.h
diff --git a/chrome/browser/ui/browser_commands.h b/chrome/browser/ui/browser_commands.h
index 984144b0ed72218fe877fdc14df7ad55711fc3bc..8cf6496906742d6648bb241b7b178907970a88c8 100644
--- a/chrome/browser/ui/browser_commands.h
+++ b/chrome/browser/ui/browser_commands.h
@@ -73,6 +73,7 @@ void NewIncognitoWindow(Browser* browser);
 void CloseWindow(Browser* browser);
 void NewTab(Browser* browser);
 void CloseTab(Browser* browser);
+int  GetZoomPercent(content::WebContents* contents);

[Tom (Use chromium acct), 2016/04/14 19:19:36]

Do these four functions that deal with WebContents belong in this file?

[Peter Kasting, 2016/04/15 00:40:36]

I don't think so, at least not for GetZoomPercent().  This is more for functions
that execute a command rather than oracles about whether a command can be
executed.

Since these all deal with Zoom, one possible place to put them is as static
methods on ZoomController.  Note that it already has something very close to
your GetZoomPercent() as GetZoomLevelForWebContents().  It also seems like a lot
of the callers of ZoomController::GetZoomPercent() are starting with a
WebContents* (as you are).  Maybe GetZoomPercent() should be replaced by a
GetZoomPercentForWebContents()?  Or maybe there should be a function to convert
zoom levels to zoom percents, so you can call GetZoomLevelForWebContents() and
then that?  Or (minor variation) maybe it should convert from a zoom factor
(instead of a zoom level) to a zoom percent, and GetZoomLevelForWebContents()
should be changed to return a zoom factor instead (since its lone caller wants
that)?

It's less clear to me where the other functions should live, since e.g. "can
zoom in" checking the current and maximum zoom levels as well as the crashed
state seems like maybe it shouldn't live in the ZoomController, but I'm not
really sure where it should live.

I would consult the components/ui/zoom OWNERS.

 bool CanZoomIn(content::WebContents* contents);
 bool CanZoomOut(content::WebContents* contents);
 bool CanResetZoom(content::WebContents* contents);