On macOS, avoid forcible activation during Show.

chrome/browser/ui/views/frame/browser_view.cc

 // Copyright 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.
 
 #include "chrome/browser/ui/views/frame/browser_view.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 #include <memory>
@@ skipping 588 matching lines @@
   // Windows and Ash, but other platforms will not trigger
   // OnWidgetActivationChanged() until we return to the runloop. Therefore any
   // calls to Browser::GetLastActive() will return the wrong result if we do not
   // explicitly set it here.
   // A similar block also appears in BrowserWindowCocoa::Show().
   BrowserList::SetLastActive(browser());
 #endif
 
   // If the window is already visible, just activate it.
   if (frame_->IsVisible()) {
+#if defined(OS_MACOSX)
+    // When opening a URL from another application, macOS will activate the
+    // browser window in the case when "Open" action is used, but won't do it
+    // in the case when "Open Behind" is requested. Let's assume macOS handles
+    // the activation for us; just put the window above other browser windows.
+    frame_->ShowInactive();
+#else
     frame_->Activate();
+#endif
     return;
   }
 
   // Showing the window doesn't make the browser window active right away.
   // This can cause SetFocusToLocationBar() to skip setting focus to the
   // location bar. To avoid this we explicilty let SetFocusToLocationBar()
   // know that it's ok to steal focus.
   force_location_bar_focus_ = true;
 
   // Setting the focus doesn't work when the window is invisible, so any focus
   // initialization that happened before this will be lost.
   //
   // We really "should" restore the focus whenever the window becomes unhidden,
   // but I think initializing is the only time where this can happen where
   // there is some focus change we need to pick up, and this is easier than
   // plumbing through an un-hide message all the way from the frame.
   //
   // If we do find there are cases where we need to restore the focus on show,
   // that should be added and this should be removed.
   RestoreFocus();
 
   frame_->Show();

[tapted, 2017/01/03 03:27:06]

This isn't quite right either. If Chrome has been hidden with [NSApp hide] (e.g.
Cmd+h) then the window won't be visible. But the window still should not
activate in that case (currently `open -a Chromium -g http://www.google.com`
after Cmd+h will move focus away)

Similarly, if there are no browser windows open, then `open -g` should not
activate the newly created window.

Unfortunately, this will not do the right thing for calls coming from
WindowsCreateFunction::Run() using the tabs extension API. We will need a
solution that fixes both.

One possible approach could be to add an appropriate WidgetDelegate method.
There is `CanActivate` but currently that means something more like
"CanAcceptKeyboardInput" which isn't right.

Perhaps

bool WidgetDelegate::WidgetActivatesApplication() const;

which defaults to `true`

BrowserView overrides this on Mac so that it returns `false` when being called
via -[AppController openUrls:] in app_controller_mac.mm

To do that.. it's a bit ugly, but there is already something similar needed in
app_controller_mac's `g_is_opening_new_window`, used by session_service.cc

So, e.g., add app_controller_mac::IsExternallyTriggeredURLOpen(), and have
-[AppController openUrls:] do something similar to CreateBrowser(..) in
app_controller_mac.mm.

The final piece is to have BridgedNativeWidget::SetVisibilityState() skip
calling `[NSApp activateIgnoringOtherApps:YES];` if the widget delegate returns
false from `WidgetActivatesApplication()`


Then add a test. There's already a bunch of stuff in
app_controller_mac_browsertest.mm for invoking openUrls:. You might need to use
a swizzler to ensure nothing is invoking [NSApp activateIgnoringOtherApps:]
rather than trying to observe the actual activation, since otherwise window
activation is pretty flaky.


Note you will still need sky@ to chime in about
WidgetDelegate::WidgetActivatesApplication() -- I think that's the neatest
option, but he might see an approach I've missed.

[sky, 2017/01/03 16:38:01]

Is the problem that there are two many random places calling show and you need a
way to alter what Show does without changing every place? And that you want to
do something like:

  make_show_not_activate_app = true;
  Show();
  make_show_not_activate_app = false;

?

 
   force_location_bar_focus_ = false;
 
   browser()->OnWindowDidShow();
 
   chrome::MaybeShowInvertBubbleView(this);
 }
 
 void BrowserView::ShowInactive() {
   if (!frame_->IsVisible())
@@ skipping 1943 matching lines @@
 }
 
 extensions::ActiveTabPermissionGranter*
 BrowserView::GetActiveTabPermissionGranter() {
   content::WebContents* web_contents = GetActiveWebContents();
   if (!web_contents)
     return nullptr;
   return extensions::TabHelper::FromWebContents(web_contents)
       ->active_tab_permission_granter();
 }