Zero-sized windows are bad.

Eliminate three instances of them, and DCHECK on the condition for the future.

BUG=none
TEST=none

Review URL: https://chromiumcodereview.appspot.com/10003005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@132280 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 45 insertions, 0 deletions

diff --git a/ui/base/cocoa/underlay_opengl_hosting_window.mm b/ui/base/cocoa/underlay_opengl_hosting_window.mm
index 6ed0624..b82decd 100644
--- a/ui/base/cocoa/underlay_opengl_hosting_window.mm
+++ b/ui/base/cocoa/underlay_opengl_hosting_window.mm
@@ -87,6 +87,20 @@ void RootDidAddSubview(id self, SEL _cmd, NSView* subview) {
                 styleMask:(NSUInteger)windowStyle
                   backing:(NSBackingStoreType)bufferingType
                     defer:(BOOL)deferCreation {
+  // It is invalid to create windows with zero width or height. It screws things
+  // up royally:
+  // - It causes console spew: <http://crbug.com/78973>
+  // - It breaks Expose: <http://sourceforge.net/projects/heat-meteo/forums/forum/268087/topic/4582610>
+  //
+  // This is a banned practice
+  // <http://www.chromium.org/developers/coding-style/cocoa-dos-and-donts>. Do
+  // not do this. Use kWindowSizeDeterminedLater in
+  // ui/base/cocoa/window_size_constants.h instead.
+  //
+  // (This is checked here because UnderlayOpenGLHostingWindow is the base of
+  // most Chromium windows, not because this is related to its functionality.)
+  DCHECK(contentRect.size.width > 0 &&
+         contentRect.size.height > 0);
   if ((self = [super initWithContentRect:contentRect
                                styleMask:windowStyle
                                  backing:bufferingType
diff --git a/ui/base/cocoa/window_size_constants.h b/ui/base/cocoa/window_size_constants.h
new file mode 100644
index 0000000..9f33336
--- /dev/null
+++ b/ui/base/cocoa/window_size_constants.h
@@ -0,0 +1,20 @@
+// 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 UI_BASE_COCOA_WINDOW_SIZE_CONSTANTS_H_
+#define UI_BASE_COCOA_WINDOW_SIZE_CONSTANTS_H_
+#pragma once
+
+#include "ui/base/ui_export.h"
+
+#import <Foundation/Foundation.h>
+
+namespace ui {
+
+// It is not valid to make a zero-sized window. Use this constant instead.
+UI_EXPORT extern const NSRect kWindowSizeDeterminedLater;
+
+}  // namespace ui
+
+#endif  // UI_BASE_COCOA_WINDOW_SIZE_CONSTANTS_H_
diff --git a/ui/base/cocoa/window_size_constants.mm b/ui/base/cocoa/window_size_constants.mm
new file mode 100644
index 0000000..c635599
--- /dev/null
+++ b/ui/base/cocoa/window_size_constants.mm
@@ -0,0 +1,11 @@
+// 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.
+
+#include "ui/base/cocoa/window_size_constants.h"
+
+namespace ui {
+
+const NSRect kWindowSizeDeterminedLater = { {0, 0}, {1, 1} };
+
+}  // namespace ui