OptimizationGuide: Add proto for DelayCompetingLowPriorityRequests

CREDIT: The most of changes were written by dom@chromium.org.

Bug: 1112515
Change-Id: I979f221adf30edbe41a3e575283ddd4c1d6105a2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2387905
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Reviewed-by: Sophie Chang <sophiechang@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Dominic Farolino <dom@chromium.org>
Cr-Commit-Position: refs/heads/master@{#804654}

chrome/browser/optimization_guide/blink/blink_optimization_guide_browsertest.cc

@@ -125,7 +125,8 @@ class BlinkOptimizationGuideBrowserTest
     switch (GetOptimizationType()) {
       case proto::OptimizationType::DELAY_ASYNC_SCRIPT_EXECUTION: {
         proto::DelayAsyncScriptExecutionMetadata metadata;
-        metadata.set_delay_type(proto::DelayType::DELAY_TYPE_FINISHED_PARSING);
+        metadata.set_delay_type(
+            proto::PerfectHeuristicsDelayType::DELAY_TYPE_FINISHED_PARSING);
         optimization_guide_metadata.SetAnyMetadataForTesting(metadata);
         break;
       }

chrome/browser/optimization_guide/blink/blink_optimization_guide_inquirer.cc

@@ -92,16 +92,22 @@ void BlinkOptimizationGuideInquirer::PopulateHintsForDelayAsyncScriptExecution(
   using blink::mojom::DelayAsyncScriptExecutionDelayType;
   auto hints = blink::mojom::DelayAsyncScriptExecutionHints::New();
   switch (metadata->delay_type()) {
-    case proto::DelayType::DELAY_TYPE_UNKNOWN:
+    case proto::PerfectHeuristicsDelayType::DELAY_TYPE_UNKNOWN:
       hints->delay_type = DelayAsyncScriptExecutionDelayType::kUnknown;
       break;
-    case proto::DelayType::DELAY_TYPE_FINISHED_PARSING:
+    case proto::PerfectHeuristicsDelayType::DELAY_TYPE_FINISHED_PARSING:
       hints->delay_type = DelayAsyncScriptExecutionDelayType::kFinishedParsing;
       break;
-    case proto::DelayType::DELAY_TYPE_FIRST_PAINT_OR_FINISHED_PARSING:
+    case proto::PerfectHeuristicsDelayType::
+        DELAY_TYPE_FIRST_PAINT_OR_FINISHED_PARSING:
       hints->delay_type =
           DelayAsyncScriptExecutionDelayType::kFirstPaintOrFinishedParsing;
       break;
+    case proto::PerfectHeuristicsDelayType::DELAY_TYPE_FIRST_PAINT:
+    case proto::PerfectHeuristicsDelayType::DELAY_TYPE_FIRST_CONTENTFUL_PAINT:
+      // DelayAsyncScriptExecution doesn't support these milestones.
+      NOTREACHED();
+      return;
   }
   DCHECK(!optimization_guide_hints_->delay_async_script_execution_hints);
   optimization_guide_hints_->delay_async_script_execution_hints =

components/optimization_guide/hints_processing_util.cc

@@ -47,6 +47,8 @@ std::string GetStringNameForOptimizationType(
       return "FastHostHints";
     case proto::OptimizationType::DELAY_ASYNC_SCRIPT_EXECUTION:
       return "DelayAsyncScriptExecution";
+    case proto::OptimizationType::DELAY_COMPETING_LOW_PRIORITY_REQUESTS:
+      return "DelayCompetingLowPriorityRequests";
     case proto::OptimizationType::LITE_VIDEO:
       return "LiteVideo";
   }

components/optimization_guide/proto/BUILD.gn

@@ -12,6 +12,7 @@ proto_library("optimization_guide_proto") {
   sources = [
     "common_types.proto",
     "delay_async_script_execution_metadata.proto",
+    "delay_competing_low_priority_requests_metadata.proto",
     "hint_cache.proto",
     "hints.proto",
     "lite_video_metadata.proto",
@@ -29,6 +30,7 @@ if (is_android) {
     sources = [
       "common_types.proto",
       "delay_async_script_execution_metadata.proto",
+      "delay_competing_low_priority_requests_metadata.proto",
       "hints.proto",
       "lite_video_metadata.proto",
       "loading_predictor_metadata.proto",

components/optimization_guide/proto/common_types.proto

@@ -9,6 +9,15 @@ option java_outer_classname = "CommonTypesProto";
 
 package optimization_guide.proto;
 
+// Loading milestones that Perfect Heuristics experiments can use as delays.
+enum PerfectHeuristicsDelayType {
+  DELAY_TYPE_UNKNOWN = 0;
+  DELAY_TYPE_FINISHED_PARSING = 1;
+  DELAY_TYPE_FIRST_PAINT_OR_FINISHED_PARSING = 2;
+  DELAY_TYPE_FIRST_PAINT = 3;
+  DELAY_TYPE_FIRST_CONTENTFUL_PAINT = 4;
+}
+
 // The possible effective connection type values.
 //
 // The values should match those of //net/nqe/effective_connection_type.h in the

components/optimization_guide/proto/delay_async_script_execution_metadata.proto

@@ -10,16 +10,10 @@ option java_outer_classname = "DelayAsyncScriptExecutionMetadataProto";
 
 package optimization_guide.proto;
 
-// Enumerates the timings at which execution of async scripts can be delayed
-// until.
-enum DelayType {
-  DELAY_TYPE_UNKNOWN = 0;
-  DELAY_TYPE_FINISHED_PARSING = 1;
-  DELAY_TYPE_FIRST_PAINT_OR_FINISHED_PARSING = 2;
-};
+import "common_types.proto";
 
 // Optimization metadata for OptimizationType::DELAY_ASYNC_SCRIPT_EXECUTION.
 message DelayAsyncScriptExecutionMetadata {
   // The timing at which execution of async scripts should be delayed until.
-  optional DelayType delay_type = 1;
+  optional PerfectHeuristicsDelayType delay_type = 1;
 }

components/optimization_guide/proto/delay_competing_low_priority_requests_metadata.proto

+// Copyright 2020 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.
+
+syntax = "proto2";
+
+option optimize_for = LITE_RUNTIME;
+option java_package = "org.chromium.components.optimization_guide.proto";
+option java_outer_classname = "DelayCompetingLowPriorityRequestsMetadataProto";
+
+package optimization_guide.proto;
+
+import "common_types.proto";
+
+// Enumerates the different request priorities that the Chromium experiment will
+// consider "important". For example, low priority requests will be queued
+// behind in-flight medium priority requests, when the PriorityThreshold is
+// PRIORITY_THRESHOLD_MEDIUM, etc.
+enum PriorityThreshold {
+  PRIORITY_THRESHOLD_UNKNOWN = 0;
+  PRIORITY_THRESHOLD_MEDIUM = 1;
+  PRIORITY_THRESHOLD_HIGH = 2;
+}
+
+// Optimization metadata for
+// OptimizationType::DELAY_COMPETING_LOW_PRIORITY_REQUESTS.
+message DelayCompetingLowPriorityRequestsMetadata {
+  optional PerfectHeuristicsDelayType delay_type = 1;
+  optional PriorityThreshold priority_threshold = 2;
+}

components/optimization_guide/proto/hints.proto

@@ -125,9 +125,9 @@ enum OptimizationType {
   // This optimization provides information about the effective delay for async
   // script execution.
   DELAY_ASYNC_SCRIPT_EXECUTION = 11;
-  // TODO(crbug/1112515): Add type here for delay low priority resources to
-  // match server.
-  //
+  // This optimization provides information about the effective delay and
+  // priority thresholds for delaying low priority requests.
+  DELAY_COMPETING_LOW_PRIORITY_REQUESTS = 12;
   // This optimization provides information about how to throttle meda requests
   // to reduce the bitrate of adaptively streamed media.
   LITE_VIDEO = 13;