Add InfoBar delegate for previews

chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_io_data.cc

 // Copyright 2015 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/net/spdyproxy/data_reduction_proxy_chrome_io_data.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
 #include "build/build_config.h"
 #include "chrome/browser/net/spdyproxy/chrome_data_use_group_provider.h"
 #include "chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.h"
+#include "chrome/browser/previews/previews_infobar_delegate.h"
 #include "chrome/common/channel_info.h"
 #include "chrome/common/chrome_content_client.h"
 #include "chrome/common/pref_names.h"
 #include "components/data_reduction_proxy/content/browser/content_lofi_decider.h"
 #include "components/data_reduction_proxy/content/browser/content_lofi_ui_service.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
 #include "components/prefs/pref_service.h"
 #include "components/version_info/version_info.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/web_contents.h"
 
 #if defined(OS_ANDROID)
 #include "base/android/build_info.h"
-#include "chrome/browser/android/tab_android.h"
 #endif
 
 namespace content {
 class BrowserContext;
 }
 
 using data_reduction_proxy::DataReductionProxyParams;
 
 namespace {
 
 // For Android builds, notifies the TabAndroid associated with |web_contents|
 // that a Lo-Fi response has been received. The TabAndroid then handles showing
 // Lo-Fi UI if this is the first Lo-Fi response for a page load. |is_preview|
 // indicates whether the response was a Lo-Fi preview response.
 void OnLoFiResponseReceivedOnUI(content::WebContents* web_contents,
                                 bool is_preview) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-#if defined(OS_ANDROID)
-  TabAndroid* tab = TabAndroid::FromWebContents(web_contents);
-  if (tab)
-    tab->OnLoFiResponseReceived(is_preview);
-#endif
+  PreviewsInfoBarDelegate::Create(web_contents,

[Peter Kasting, 2016/08/23 19:48:17]

Is this code accessible on non-Android builds?

Right now the resources, enum values, implementation locations, etc. are all
done in cross-platform ways, but it seems as if this is maybe an
Android-specific thing.  If it is, we want to make that as clear as possible and
avoid compiling in this stuff for the other platforms.

[megjablon, 2016/08/23 23:54:16]

Right now we can enable previews on desktop via a command line flag and
chrome://flags. We've always had the context menu items for it, but not the
infobar. bengr@ what do you think about having this on desktop? Will we need it
from a product standpoint? It's particularly useful for testing and debugging.

[Peter Kasting, 2016/08/24 03:18:27]

I am OK with resolving this issue as a follow-up, but do strive to resolve it --
we've had a lot of confusion and trouble over the years with
seemingly-cross-platform code that turned out to be Android-only in practice, so
either being clearly Android-only or else actually working on all platforms are
better end states.

[megjablon, 2016/08/24 21:44:29]

The code fully works on all platforms so it doesn't fall into the
seemingly-cross-platform bucket. This UI was the only part of the feature living
in Android before and now we can display it on desktop too. 

+                                  is_preview ? PreviewsInfoBarDelegate::PREVIEW
+                                             : PreviewsInfoBarDelegate::LOFI);
 }
 
 } // namespace
 
 std::unique_ptr<data_reduction_proxy::DataReductionProxyIOData>
 CreateDataReductionProxyChromeIOData(
     net::NetLog* net_log,
     PrefService* prefs,
     const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner,
     const scoped_refptr<base::SingleThreadTaskRunner>& ui_task_runner) {
@@ skipping 26 matching lines @@
   data_reduction_proxy_io_data->set_lofi_decider(
       base::WrapUnique(new data_reduction_proxy::ContentLoFiDecider()));
   data_reduction_proxy_io_data->set_lofi_ui_service(
       base::WrapUnique(new data_reduction_proxy::ContentLoFiUIService(
           ui_task_runner, base::Bind(&OnLoFiResponseReceivedOnUI))));
   data_reduction_proxy_io_data->set_data_usage_source_provider(
       base::WrapUnique(new ChromeDataUseGroupProvider()));
 
   return data_reduction_proxy_io_data;
 }