New CPAT support in DataReductionProxyConfig guarded by feature flag.

components/data_reduction_proxy/core/browser/data_reduction_proxy_config.cc

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_config.cc
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.cc
index 54bcda83261d17f3cb7e89582f11fac82a8cb368..098e7c69ec8b7ab08b0e182b89278e3055bbf346 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.cc
@@ -27,6 +27,7 @@
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_configurator.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_config_values.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_event_creator.h"
+#include "components/data_reduction_proxy/core/common/data_reduction_proxy_features.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
 #include "components/data_use_measurement/core/data_use_user_data.h"
 #include "components/previews/core/previews_decider.h"
@@ -965,6 +966,10 @@ bool DataReductionProxyConfig::ShouldEnableLoFi(
   DCHECK((request.load_flags() & net::LOAD_MAIN_FRAME_DEPRECATED) != 0);
   DCHECK(!request.url().SchemeIsCryptographic());
 
+  if (base::FeatureList::IsEnabled(
+          features::kDataReductionProxyDecidesTransform))
+    return ShouldAcceptServerLoFi(request, previews_decider);
+
   bool enable_lofi = ShouldEnableLoFiInternal(request, previews_decider);
 
   if (params::IsLoFiSlowConnectionsOnlyViaFlags() ||
@@ -985,6 +990,10 @@ bool DataReductionProxyConfig::ShouldEnableLitePages(
   DCHECK((request.load_flags() & net::LOAD_MAIN_FRAME_DEPRECATED) != 0);
   DCHECK(!request.url().SchemeIsCryptographic());
 
+  if (base::FeatureList::IsEnabled(
+          features::kDataReductionProxyDecidesTransform))
+    return ShouldAcceptLitePages(request, previews_decider);
+
   return ShouldEnableLitePagesInternal(request, previews_decider);
 }
 
@@ -993,10 +1002,101 @@ bool DataReductionProxyConfig::enabled_by_user_and_reachable() const {
   return enabled_by_user_ && !unreachable_;
 }
 
+bool DataReductionProxyConfig::ShouldAcceptServerLoFi(
+    const net::URLRequest& request,
+    previews::PreviewsDecider* previews_decider) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(base::FeatureList::IsEnabled(
+      features::kDataReductionProxyDecidesTransform));
+
+  // LitePages overrides Server Lo-Fi. Server will direct Server Lo-Fi for
+  // resources if applicable.
+  if (ShouldEnableLitePages(request, previews_decider)) {
+    return false;
+  }
+
+  // Make sure request is not locally blacklisted.

[bengr, 2017/05/19 20:20:47]

These functions have a lot of duplicate code, which should be refactored into a
helper method. Ideally, though these two methods would have 100% overlap. It
seems flags asymmetry is the reason they don't. Ryan is refactoring flags. Can
you sync with him? If you build on top of his work, we can probably change these
to 'bool ShouldAcceptServerPreviews(previews::PreviewsType type, ...)'

[dougarnett, 2017/05/19 21:43:58]

I agree on merit of refactoring along with cleaning up flags. Doesn't seem to be
in scope of this change though - these are actually simpler that the
corresponding *Internal() methods and keeping them similar initially helps
compare them. I can clean up after Ryan consolidates flags if he does not do
such clean-up here as part of the consolidation.

[dougarnett, 2017/05/19 22:29:58]

Ok, have factored just this blacklist and loff_off_ check (with verbage) into a
helper method. Also made entry on Ryan's TODO bug wrt not wanting ECT after all
actually.

+  if (params::IsBlackListEnabledForServerPreviews()) {
+    // Pass in net::EFFECTIVE_CONNECTION_TYPE_4G as the thresold as network
+    // speed is checked in IsNetworkQualityProhibitivelySlow().
+    // TODO(ryansturm): Use the correct ECT value. crbug.com/720102
+    if (!previews_decider->ShouldAllowPreviewAtECT(
+            request, previews::PreviewsType::LOFI,
+            net::EFFECTIVE_CONNECTION_TYPE_4G)) {
+      return false;
+    }
+  } else if (lofi_off_) {
+    // If Lo-Fi has been turned off, its status can't change. This Lo-Fi bit
+    // will be removed when Lo-Fi and Lite Pages are moved over to using the
+    // PreviewsBlackList.
+    return false;
+  }
+
+  if (params::IsLoFiAlwaysOnViaFlags())
+    return true;
+
+  if (params::IsLoFiCellularOnlyViaFlags()) {
+    return net::NetworkChangeNotifier::IsConnectionCellular(connection_type_);
+  }
+
+  if (params::IsLoFiSlowConnectionsOnlyViaFlags() ||
+      params::IsIncludedInLoFiEnabledFieldTrial()) {
+    // Accept Lo-Fi from the data reduction proxy (it will handle the effective
+    // connection type check).
+    return true;
+  }
+
+  return false;
+}
+
+bool DataReductionProxyConfig::ShouldAcceptLitePages(
+    const net::URLRequest& request,
+    previews::PreviewsDecider* previews_decider) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(base::FeatureList::IsEnabled(
+      features::kDataReductionProxyDecidesTransform));
+
+  if (params::IsBlackListEnabledForServerPreviews()) {
+    // Pass in net::EFFECTIVE_CONNECTION_TYPE_4G as the thresold as network
+    // speed is checked in IsNetworkQualityProhibitivelySlow().
+    // TODO(ryansturm): Use the correct ECT value. crbug.com/720102
+    if (!previews_decider->ShouldAllowPreviewAtECT(
+            request, previews::PreviewsType::LITE_PAGE,
+            net::EFFECTIVE_CONNECTION_TYPE_4G)) {
+      return false;
+    }
+  } else if (lofi_off_) {
+    // If Lo-Fi has been turned off, its status can't change. This Lo-Fi bit
+    // will be removed when Lo-Fi and Lite Pages are moved over to using the
+    // PreviewsBlackList.
+    return false;
+  }
+
+  if (params::IsLoFiAlwaysOnViaFlags() && params::AreLitePagesEnabledViaFlags())
+    return true;
+
+  if (params::IsLoFiCellularOnlyViaFlags() &&
+      params::AreLitePagesEnabledViaFlags()) {
+    return net::NetworkChangeNotifier::IsConnectionCellular(connection_type_);
+  }
+
+  if ((params::IsLoFiSlowConnectionsOnlyViaFlags() &&
+       params::AreLitePagesEnabledViaFlags()) ||
+      params::IsIncludedInLitePageFieldTrial()) {
+    // Accept LitePages from the data reduction proxy (it will handle the
+    // effective connection type check).
+    return true;
+  }
+
+  return false;
+}
+
 bool DataReductionProxyConfig::ShouldEnableLoFiInternal(
     const net::URLRequest& request,
     previews::PreviewsDecider* previews_decider) {
   DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(!base::FeatureList::IsEnabled(
+      features::kDataReductionProxyDecidesTransform));
 
   last_query_ = GetTicksNow();
   network_quality_at_last_query_ = NETWORK_QUALITY_AT_LAST_QUERY_UNKNOWN;
@@ -1042,6 +1142,8 @@ bool DataReductionProxyConfig::ShouldEnableLitePagesInternal(
     const net::URLRequest& request,
     previews::PreviewsDecider* previews_decider) {
   DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(!base::FeatureList::IsEnabled(
+      features::kDataReductionProxyDecidesTransform));
 
   if (params::IsBlackListEnabledForServerPreviews()) {
     // Pass in net::EFFECTIVE_CONNECTION_TYPE_4G as the thresold as network