Update CPAT protocol to send lite-page transform acceptance with ect

components/data_reduction_proxy/core/common/lofi_decider.h

 // 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.
 
-#ifndef COMPONENTS_DATA_REDUCTION_PROXY_CORE_BROWSER_LOFI_DECIDER_H_
-#define COMPONENTS_DATA_REDUCTION_PROXY_CORE_BROWSER_LOFI_DECIDER_H_
+#ifndef COMPONENTS_DATA_REDUCTION_PROXY_CORE_COMMON_LOFI_DECIDER_H_
+#define COMPONENTS_DATA_REDUCTION_PROXY_CORE_COMMON_LOFI_DECIDER_H_
 
 #include "base/macros.h"
 
 namespace net {
 class HttpRequestHeaders;
 class URLRequest;
 }
 
 namespace data_reduction_proxy {
 
 // Interface to determine if a request should be made for a low fidelity version
 // of the resource.
 class LoFiDecider {
  public:
   virtual ~LoFiDecider() {}
 
   // Returns true when Lo-Fi Previews are on for the given |request|. This means
   // the Lo-Fi header should be added to the given request.
   virtual bool IsUsingLoFi(const net::URLRequest& request) const = 0;
 
   // Adds a previews-specific directive to the Chrome-Proxy-Accept-Transform
-  // header if needed. If a slow page preview is triggered, adds "lite-page" or
+  // header if needed. If a preview is triggered, adds "lite-page" or
   // "empty-image", depending on whether the request is for the main frame
   // and lite pages are enabled, or for a subresource and Lo-Fi mode is enabled,
-  // respectively. If a slow page preview is not triggered, "lite-page;if-heavy"
-  // and "empty-image;if-heavy" are added in the respective aforementioned cases
-  // to request that the server transform the page if it determines it to be
-  // heavy. Previews-related transformation headers are never added if
-  // |is_previews_disabled| is true.
+  // respectively.
   virtual void MaybeSetAcceptTransformHeader(
       const net::URLRequest& request,

[bengr, 2017/05/01 16:53:14]

This doesn't need the whole request. It uses the resource type and the url
scheme, so it would be better to pass those in directly.

-      bool are_previews_disabled,
       net::HttpRequestHeaders* headers) const = 0;
 
   // Returns true if |headers| contains the Chrome-Proxy-Accept-Transform
   // header and a slow page previews directive ("lite-page" or "empty-image")
   // is present and not conditioned on "if-heavy".
   virtual bool IsSlowPagePreviewRequested(
       const net::HttpRequestHeaders& headers) const = 0;
 
   // Returns true if |headers| contains the Chrome-Proxy-Accept-Transform
   // header with the "lite-page" directive.
   virtual bool IsLitePagePreviewRequested(
       const net::HttpRequestHeaders& headers) const = 0;
 
   // Unconditionally removes the Chrome-Proxy-Accept-Transform header from
   // |headers.|
   virtual void RemoveAcceptTransformHeader(
       net::HttpRequestHeaders* headers) const = 0;
 
-  // Adds a directive to tell the server to ignore blacklists when a Lite Page
-  // preview is being requested due to command line flags being set.
-  virtual void MaybeSetIgnorePreviewsBlacklistDirective(
+  // Adds a directive to tell the server to return a Lite Page preview due to
+  // command line flags being set (in spite of a good network connection, the

[bengr, 2017/05/01 16:53:14]

I would stay away from commenting on the types of signals we use to trigger lite
page. Maybe:

// Adds a directive to tell the server to return a Lite Page preview
unconditionally. 

+  // page being blacklisted, or the page not being heavy).
+  virtual void MaybeSetForceLitePageDirective(
       net::HttpRequestHeaders* headers) const = 0;
 
-  // Returns true if the Lo-Fi specific UMA should be recorded. It is set to
-  // true if Lo-Fi is enabled for |request|, Chrome session is in Lo-Fi
-  // Enabled or Control field trial, and the network quality was slow.
-  virtual bool ShouldRecordLoFiUMA(const net::URLRequest& request) const = 0;
+  // Returns true if the Previews specific UMA should be recorded. It is set to

[bengr, 2017/05/01 16:53:14]

Previews specific -> Previews-specific

Also, preview and previews should be case-consistent everywhere. Maybe use lower
case?

+  // true if Lo-Fi is enabled for |request| and Chrome session is in Lo-Fi
+  // Enabled or Control field trial.
+  virtual bool ShouldRecordPreviewsUMA(
+      const net::URLRequest& request) const = 0;
 };
 
 }  // namespace data_reduction_proxy
 
-#endif  // COMPONENTS_DATA_REDUCTION_PROXY_CORE_BROWSER_LOFI_DECIDER_H_
+#endif  // COMPONENTS_DATA_REDUCTION_PROXY_CORE_COMMON_LOFI_DECIDER_H_