Update comments in InstallableManager.

chrome/browser/installable/installable_manager.cc

 // Copyright 2016 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/installable/installable_manager.h"
 
 #include "base/bind.h"
 #include "base/strings/string_util.h"
 #include "chrome/browser/manifest/manifest_icon_downloader.h"
 #include "chrome/browser/manifest/manifest_icon_selector.h"
 #include "chrome/browser/profiles/profile.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/service_worker_context.h"
 #include "content/public/browser/storage_partition.h"
 #include "third_party/WebKit/public/platform/WebDisplayMode.h"
 
 namespace {
 
 const char kPngExtension[] = ".png";
 
 // This constant is the icon size on Android (48dp) multiplied by the scale
 // factor of a Nexus 5 device (3x). For mobile and desktop platforms, a 144px
-// icon is an approximate, appropriate lower bound.
+// icon is an approximate, appropriate lower bound. It is the currently
+// advertised minimum icon size for triggering banners.
 // TODO(dominickn): consolidate with minimum_icon_size_in_dp across platforms.
 const int kIconMinimumSizeInPx = 144;
 
 // Returns true if |manifest| specifies a PNG icon >= 144x144px (or size "any").
 bool DoesManifestContainRequiredIcon(const content::Manifest& manifest) {
   for (const auto& icon : manifest.icons) {
     // The type field is optional. If it isn't present, fall back on checking
     // the src extension, and allow the icon if the extension ends with png.
     if (!base::EqualsASCII(icon.type, "image/png") &&
         !(icon.type.empty() && base::EndsWith(
@@ skipping 399 matching lines @@
   return manifest_->url;
 }
 
 const content::Manifest& InstallableManager::manifest() const {
   return manifest_->manifest;
 }
 
 bool InstallableManager::is_installable() const {
   return installable_->installable;
 }