Change browser/page action default icon defined in manifest to support hidpi.

chrome/browser/extensions/extension_action_icon_factory.cc

+// 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 "chrome/browser/extensions/extension_action_icon_factory.h"
+
+#include "chrome/common/extensions/extension.h"
+#include "chrome/common/extensions/extension_action.h"
+#include "chrome/common/extensions/extension_icon_set.h"
+#include "grit/theme_resources.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/gfx/image/image_skia.h"
+
+using extensions::Extension;
+using extensions::IconImage;
+
+namespace {
+
+int GetIconSizeForType(ExtensionAction::Type type) {
+  switch (type) {
+    case ExtensionAction::TYPE_BROWSER:
+    case ExtensionAction::TYPE_PAGE:
+      return extension_misc::EXTENSION_ICON_ACTION;
+    case ExtensionAction::TYPE_SCRIPT_BADGE:
+      return extension_misc::EXTENSION_ICON_BITTY;
+    default:
+      NOTREACHED();
+      return 0;
+  }
+}
+
+gfx::ImageSkia GetDefaultIcon() {
+  return *ui::ResourceBundle::GetSharedInstance().GetImageNamed(
+      IDR_EXTENSIONS_FAVICON).ToImageSkia();
+}
+
+}  // namespace
+
+ExtensionActionIconFactory::ExtensionActionIconFactory(
+    const Extension* extension, Observer* observer)
+    : extension_(extension),
+      observer_(observer) {
+}
+
+ExtensionActionIconFactory::~ExtensionActionIconFactory() {}
+
+// extensions::IconImage::Observer overrides.
+void ExtensionActionIconFactory::OnExtensionIconImageChanged(IconImage* image) {
+  if (observer_)
+    observer_->OnIconUpdated();
+}
+
+gfx::Image ExtensionActionIconFactory::GetIcon(
+    const ExtensionAction* action,
+    int tab_id) {
+  gfx::ImageSkia base_icon = GetBaseIconFromAction(action, tab_id);
+  return action->ApplyAttentionAndAnimation(base_icon, tab_id);
+}
+
+gfx::ImageSkia ExtensionActionIconFactory::GetBaseIconFromAction(
+    const ExtensionAction* action,
+    int tab_id) {
+  gfx::ImageSkia icon = action->GetExplicitlySetIcon(tab_id);
+  if (!icon.isNull())
+    return icon;
+  if (action->default_icon()) {
+    // If icon set hasn't changed, return the present icon.

[Jeffrey Yasskin, 2012/09/14 23:47:12]

If GetIcon() is called with two different ExtensionActions, it looks like this
will always return the default icon of the first one. Can you set the
ExtensionAction as a constructor argument instead?

[tbarzic, 2012/09/15 00:29:10]

Done.

+    if (icon_.get()) {
+      return icon_->image_skia();
+    }
+
+    icon_.reset(new IconImage(extension_,

[Jeffrey Yasskin, 2012/09/14 23:47:12]

I see a path from the observer callback through
BrowserActionButton::UpdateState() back into GetIcon(). I think there's no way
that callback can actually cause the IconImage to be re-created, but it deserves
a comment at the very least, and I'd be happier if the 'new' weren't callable
from this path at all.

[tbarzic, 2012/09/15 00:29:10]

if I get your comment correctly, you're afraid that we could  recreate
icon_image when the observer is invoked?
If that's true: "if (icon_.get())" above should guard as against that.

+                              *action->default_icon(),
+                              GetIconSizeForType(action->action_type()),
+                              GetDefaultIcon(),
+                              this));
+    return icon_->image_skia();
+  }
+
+  return GetDefaultIcon();
+}
+