Add a bare-bones extension shelf that displays extension items on OS X.

chrome/browser/cocoa/extension_view_mac.mm

Index: chrome/browser/cocoa/extension_view_mac.mm
diff --git a/chrome/browser/cocoa/extension_view_mac.mm b/chrome/browser/cocoa/extension_view_mac.mm
new file mode 100644
index 0000000000000000000000000000000000000000..a64eee88a679de62f64f621e56a90a344973590f
--- /dev/null
+++ b/chrome/browser/cocoa/extension_view_mac.mm
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+// Copyright (c) 2009 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/cocoa/extension_view_mac.h"
+
+#include "chrome/browser/extensions/extension_host.h"
+#include "chrome/browser/renderer_host/render_view_host.h"
+#include "chrome/browser/renderer_host/render_widget_host_view_mac.h"
+
+ExtensionViewMac::ExtensionViewMac(ExtensionHost* extension_host,
+                                   Browser* browser)
+    : is_toolstrip_(true),
+      browser_(browser),
+      extension_host_(extension_host),
+      render_widget_host_view_(NULL) {
+  DCHECK(extension_host_);
+}
+
+ExtensionViewMac::~ExtensionViewMac() {
+  if (render_widget_host_view_)
+    [render_widget_host_view_->native_view() release];
+}
+
+void ExtensionViewMac::Init() {
+  CreateWidgetHostView();
+}
+
+gfx::NativeView ExtensionViewMac::native_view() {
+  DCHECK(render_widget_host_view_);
+  return render_widget_host_view_->native_view();
+}
+
+RenderViewHost* ExtensionViewMac::render_view_host() const {
+  return extension_host_->render_view_host();
+}
+
+void ExtensionViewMac::SetBackground(const SkBitmap& background) {
+  DCHECK(render_widget_host_view_);
+  render_widget_host_view_->SetBackground(background);
+}
+
+void ExtensionViewMac::UpdatePreferredWidth(int pref_width) {
+  // TODO(thakis, erikkay): Windows does some tricks to resize the extension
+  // view not before it's visible. Do something similar here.
+
+  // No need to use CA here, our caller calls us repeatedly to animate the
+  // resizing.
+  NSView* view = native_view();
+  NSRect frame = [view frame];
+  frame.size.width = pref_width;
+
+  // RenderWidgetHostViewCocoa overrides setFrame but not setFrameSize.
+  [view setFrame:frame];
+  [view setNeedsDisplay:YES];
+}
+
+void ExtensionViewMac::CreateWidgetHostView() {
+  DCHECK(!render_widget_host_view_);
+  render_widget_host_view_ = new RenderWidgetHostViewMac(render_view_host());
+
+  // The RenderWidgetHostViewMac is owned by its native view, which is created
+  // in an autoreleased state. retain it, so that it doesn't immediately
+  // disappear.
+  [render_widget_host_view_->native_view() retain];
+
+  extension_host_->CreateRenderView(render_widget_host_view_);
+}