Mac: Do layout before adding the WebContents to the view hierarchy when switching tabs

chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm

Index: chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
diff --git a/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm b/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
index 44d1d9808a484e1df8a12a9caa4b2dfdab503528..3a19757dd342ae08eb8e99b1ce750a0081d98faf 100644
--- a/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
+++ b/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
@@ -580,43 +580,22 @@ private:
   // positions.
   ScopedCAActionDisabler ca_disabler;
 
-  // Resize the new view to fit the window. Calling |view| may lazily
-  // instantiate the TabContentsController from the nib. Until we call
-  // |-ensureContentsVisible|, the controller doesn't install the RWHVMac into
-  // the view hierarchy. This is in order to avoid sending the renderer a
-  // spurious default size loaded from the nib during the call to |-view|.
-  NSView* newView = [controller view];
-
-  // Turns content autoresizing off, so removing and inserting views won't
-  // trigger unnecessary content relayout.
-  [controller ensureContentsSizeDoesNotChange];
-
-  // Remove the old view from the view hierarchy. We know there's only one
-  // child of |switchView_| because we're the one who put it there. There
-  // may not be any children in the case of a tab that's been closed, in
-  // which case there's no swapping going on.
-  NSArray* subviews = [switchView_ subviews];
-  if ([subviews count]) {
-    NSView* oldView = [subviews objectAtIndex:0];
-    // Set newView frame to the oldVew frame to prevent NSSplitView hosting
-    // sidebar and tab content from resizing sidebar's content view.
-    // ensureContentsVisible (see below) sets content size and autoresizing
-    // properties.
-    [newView setFrame:[oldView frame]];
-    // Remove the old view first, to ensure ConstrainedWindowSheets keyed to the
-    // old WebContents are removed before adding new ones.
-    [oldView removeFromSuperview];
-    [switchView_ addSubview:newView];
-  } else {
-    [newView setFrame:[switchView_ bounds]];
-    [switchView_ addSubview:newView];
-  }
+  // Ensure the nib is loaded. Sizing won't occur until it's added to the view
+  // hierarchy with -ensureContentsVisibleInSuperview:.
+  [controller view];
+
+  // Remove the old view from the view hierarchy to suppress resizes. We know
+  // there's only one child of |switchView_| because we're the one who put it
+  // there. There may not be any children in the case of a tab that's been
+  // closed, in which case there's nothing removed.
+  [[[switchView_ subviews] firstObject] removeFromSuperview];
 
-  // New content is in place, delegate should adjust itself accordingly.
+  // Prepare the container with any infobars or docked devtools it wants.
   [delegate_ onActivateTabWithContents:[controller webContents]];
 
-  // It also restores content autoresizing properties.
-  [controller ensureContentsVisible];
+  // Sizes the WebContents to match the possibly updated size of |switchView_|,
+  // then adds it and starts auto-resizing again.
+  [controller ensureContentsVisibleInSuperview:switchView_];
 }
 
 // Create a new tab view and set its cell correctly so it draws the way we want