[AssistData] Add fieldtrial param to stress test experiment

AX-Relnotes: N/A Bug: b/303655535 Change-Id: Ibac27b3a4f62912bdf2d302fdd76aa30e0fb1c7c Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5087735 Reviewed-by: Akihiro Ota <akihiroota@chromium.org> Commit-Queue: Mark Schillaci <mschillaci@google.com> Cr-Commit-Position: refs/heads/main@{#1233603}
qweri0p · Dec 5, 2023 · 367e4eb · 367e4eb
1 parent 0dd3e4a
commit 367e4eb
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Showing 4 changed files with 114 additions and 2 deletions.
diff --git a/content/browser/accessibility/snapshot_ax_tree_browsertest.cc b/content/browser/accessibility/snapshot_ax_tree_browsertest.cc
@@ -601,4 +601,58 @@ IN_PROC_BROWSER_TEST_F(SnapshotAXTreeBrowserTest, Metadata) {
           "<script type=\"application/ld+json\">{}</script>"));
 }
 
+// For Android, test the field trial param to change the number of max nodes.
+#if BUILDFLAG(IS_ANDROID)
+class SnapshotAXTreeMaxNodesParamBrowserTest : public ContentBrowserTest {
+ public:
+  SnapshotAXTreeMaxNodesParamBrowserTest() {
+    scoped_feature_list_.InitAndEnableFeatureWithParameters(
+        features::kAccessibilitySnapshotStressTests,
+        {{"AccessibilitySnapshotStressTestsMaxNodes", "500"}});
+  }
+  ~SnapshotAXTreeMaxNodesParamBrowserTest() override = default;
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
+};
+
+IN_PROC_BROWSER_TEST_F(SnapshotAXTreeMaxNodesParamBrowserTest, MaxNodes) {
+  GURL url(R"HTML(data:text/html,<body>
+                  <style> p { margin: 50px; } </style>
+                  <script>
+                    let outerDiv = document.createElement('div');
+                    for (let i = 0; i < 200; i++) {
+                      let div = document.createElement('div');
+                      for (let j = 0; j < 20; j++) {
+                        let p = document.createElement('p');
+                        p.innerHTML = j;
+                        div.appendChild(p);
+                      }
+                      outerDiv.appendChild(div);
+                    }
+                    document.body.appendChild(outerDiv);
+                  </script>
+                  </body>)HTML");
+  EXPECT_TRUE(NavigateToURL(shell(), url));
+
+  WebContentsImpl* web_contents =
+      static_cast<WebContentsImpl*>(shell()->web_contents());
+
+  AXTreeSnapshotWaiter waiter;
+  web_contents->RequestAXTreeSnapshot(
+      base::BindOnce(&AXTreeSnapshotWaiter::ReceiveSnapshot,
+                     base::Unretained(&waiter)),
+      ui::kAXModeComplete,
+      /* max_nodes= */ 10,
+      /* timeout= */ {});
+  waiter.Wait();
+
+  // If the feature flag and param was honored, we should see more than 100
+  // nodes (which was the value set on the method call), but less than all the
+  // possible nodes.
+  EXPECT_GT(waiter.snapshot().nodes.size(), 100U);
+  EXPECT_LT(waiter.snapshot().nodes.size(), 800U);
+}
+
+#endif
 }  // namespace content
diff --git a/content/renderer/accessibility/ax_tree_snapshotter_impl.cc b/content/renderer/accessibility/ax_tree_snapshotter_impl.cc
@@ -4,6 +4,7 @@
 
 #include "content/renderer/accessibility/ax_tree_snapshotter_impl.h"
 
+#include "base/metrics/field_trial_params.h"
 #include "base/metrics/histogram_functions.h"
 #include "base/task/thread_pool.h"
 #include "base/time/time.h"
@@ -147,9 +148,19 @@ bool AXTreeSnapshotterImpl::SerializeTreeWithLimits(
 }
 
 bool AXTreeSnapshotterImpl::SerializeTree(ui::AXTreeUpdate* response) {
+#if !BUILDFLAG(IS_ANDROID)
+  int max_nodes_count = 0;
+#else
+  // Experiment with different max values for end-to-end timing. An arbitrarily
+  // large value will simulate there being no max nodes count.
+  int max_nodes_count = base::GetFieldTrialParamByFeatureAsInt(
+      features::kAccessibilitySnapshotStressTests,
+      "AccessibilitySnapshotStressTestsMaxNodes", 100000);
+#endif
+
   base::ElapsedTimer timer = base::ElapsedTimer();
   timer.start_time();
-  if (!context_->SerializeEntireTree(0, {}, response)) {
+  if (!context_->SerializeEntireTree(max_nodes_count, {}, response)) {
     return false;
   }
 

diff --git a/testing/variations/fieldtrial_testing_config.json b/testing/variations/fieldtrial_testing_config.json
@@ -70,7 +70,46 @@
             ],
             "experiments": [
                 {
-                    "name": "Enabled_20231108",
+                    "name": "Enabled_Max3500_20231206",
+                    "params": {
+                        "AccessibilitySnapshotStressTestsMaxNodes": "3500"
+                    },
+                    "enable_features": [
+                        "AccessibilitySnapshotStressTests"
+                    ]
+                },
+                {
+                    "name": "Enabled_Max2000_20231206",
+                    "params": {
+                        "AccessibilitySnapshotStressTestsMaxNodes": "2000"
+                    },
+                    "enable_features": [
+                        "AccessibilitySnapshotStressTests"
+                    ]
+                },
+                {
+                    "name": "Enabled_Max1500_20231206",
+                    "params": {
+                        "AccessibilitySnapshotStressTestsMaxNodes": "1500"
+                    },
+                    "enable_features": [
+                        "AccessibilitySnapshotStressTests"
+                    ]
+                },
+                {
+                    "name": "Enabled_Max1000_20231206",
+                    "params": {
+                        "AccessibilitySnapshotStressTestsMaxNodes": "1000"
+                    },
+                    "enable_features": [
+                        "AccessibilitySnapshotStressTests"
+                    ]
+                },
+                {
+                    "name": "Control_NoMax_20231206",
+                    "params": {
+                        "AccessibilitySnapshotStressTestsMaxNodes": "100000"
+                    },
                     "enable_features": [
                         "AccessibilitySnapshotStressTests"
                     ]

diff --git a/ui/accessibility/accessibility_features.h b/ui/accessibility/accessibility_features.h
@@ -7,6 +7,7 @@
 #define UI_ACCESSIBILITY_ACCESSIBILITY_FEATURES_H_
 
 #include "base/feature_list.h"
+#include "base/metrics/field_trial_params.h"
 #include "build/build_config.h"
 #include "build/chromeos_buildflags.h"
 #include "ui/accessibility/ax_base_export.h"
@@ -189,6 +190,13 @@ AX_BASE_EXPORT bool IsAccessibilityPerformanceFilteringEnabled();
 // AXTreeSnapshotter's Snapshot method, and track related histograms.
 AX_BASE_EXPORT BASE_DECLARE_FEATURE(kAccessibilitySnapshotStressTests);
 AX_BASE_EXPORT bool IsAccessibilitySnapshotStressTestsEnabled();
+// Controls the maximum amount of nodes in a given snapshot. We set an
+// arbitrarily high value as the default to simulate there being no max nodes
+// limit.
+AX_BASE_EXPORT const base::FeatureParam<int>
+    kAccessibilitySnapshotStressTestsMaxNodes{
+        &kAccessibilitySnapshotStressTests,
+        "AccessibilitySnapshotStressTestsMaxNodes", 100000};
 #endif  // BUILDFLAG(IS_ANDROID)
 
 #if !BUILDFLAG(IS_ANDROID)