Log to UMA why we would load a third-party frame

third_party/WebKit/Source/web/tests/DeferredLoadingTest.cpp

Index: third_party/WebKit/Source/web/tests/DeferredLoadingTest.cpp
diff --git a/third_party/WebKit/Source/web/tests/DeferredLoadingTest.cpp b/third_party/WebKit/Source/web/tests/DeferredLoadingTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..911ad3bc4745d7fe61d31ef5d93e756f5234c970
--- /dev/null
+++ b/third_party/WebKit/Source/web/tests/DeferredLoadingTest.cpp
@@ -0,0 +1,187 @@
+// Copyright 2016 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 "platform/testing/HistogramTester.h"
+#include "platform/testing/UnitTestHelpers.h"
+#include "web/WebViewImpl.h"
+#include "web/tests/sim/SimCompositor.h"
+#include "web/tests/sim/SimDisplayItemList.h"
+#include "web/tests/sim/SimRequest.h"
+#include "web/tests/sim/SimTest.h"
+
+namespace blink {
+
+static const char* kHistogramName =
+    "Navigation.DeferredDocumentLoading.StatesV2";
+
+class DeferredLoadingTest : public SimTest {
+ protected:
+  DeferredLoadingTest() { webView().resize(WebSize(640, 480)); }
+  void compositeFrame() {
+    compositor().beginFrame();
+    testing::runPendingTasks();
+    if (compositor().needsBeginFrame())
+      compositor().beginFrame();  // VisibleNestedInRight doesn't need this.
+    ASSERT_FALSE(compositor().needsBeginFrame());
+  }
+
+  std::unique_ptr<SimRequest> createMainResource() {
+    std::unique_ptr<SimRequest> mainResource =
+        wrapUnique(new SimRequest("https://example.com/", "text/html"));
+    loadURL("https://example.com/");
+    return mainResource;
+  }
+};
+
+TEST_F(DeferredLoadingTest, Visible) {
+  HistogramTester histogramTester;
+  std::unique_ptr<SimRequest> mainResource = createMainResource();
+
+  mainResource->complete("<iframe sandbox></iframe>");
+
+  compositeFrame();
+
+  histogramTester.expectBucketCount(kHistogramName, Created, 1);
+  histogramTester.expectBucketCount(kHistogramName, WouldLoadVisible, 1);
+}
+
+TEST_F(DeferredLoadingTest, Right) {
+  HistogramTester histogramTester;
+  std::unique_ptr<SimRequest> mainResource = createMainResource();
+
+  mainResource->complete(
+      "<iframe style='position:absolute; left:105vw;' sandbox></iframe>");
+
+  compositeFrame();
+
+  histogramTester.expectBucketCount(kHistogramName, Created, 1);
+  histogramTester.expectTotalCount(kHistogramName, 1);
+}
+
+TEST_F(DeferredLoadingTest, Below) {
+  HistogramTester histogramTester;
+  std::unique_ptr<SimRequest> mainResource = createMainResource();
+
+  mainResource->complete(
+      "<iframe style='position:absolute; top:105vh;' sandbox></iframe>");
+
+  compositeFrame();
+
+  histogramTester.expectBucketCount(kHistogramName, Created, 1);
+  histogramTester.expectTotalCount(kHistogramName, 1);
+}
+
+TEST_F(DeferredLoadingTest, Above) {
+  HistogramTester histogramTester;
+  std::unique_ptr<SimRequest> mainResource = createMainResource();
+
+  mainResource->complete(
+      "<iframe style='position:absolute; top:-10000px;' sandbox></iframe>");
+
+  compositeFrame();
+
+  histogramTester.expectBucketCount(kHistogramName, Created, 1);
+  histogramTester.expectBucketCount(kHistogramName, WouldLoadAbove, 1);
+}
+
+TEST_F(DeferredLoadingTest, Left) {
+  HistogramTester histogramTester;
+  std::unique_ptr<SimRequest> mainResource = createMainResource();
+
+  mainResource->complete(
+      "<iframe style='position:absolute; left:-10000px;' sandbox></iframe>");
+
+  compositeFrame();
+
+  histogramTester.expectBucketCount(kHistogramName, Created, 1);
+  histogramTester.expectBucketCount(kHistogramName, WouldLoadLeft, 1);
+}
+
+TEST_F(DeferredLoadingTest, AboveAndLeft) {
+  HistogramTester histogramTester;
+  std::unique_ptr<SimRequest> mainResource = createMainResource();
+
+  mainResource->complete(
+      "<iframe style='position:absolute; left:-10000px; top:-10000px' sandbox>"
+      "</iframe>");
+
+  compositeFrame();
+
+  // Don't log WouldLoadAbove AND WouldLoadLeft.
+  histogramTester.expectBucketCount(kHistogramName, Created, 1);
+  histogramTester.expectBucketCount(kHistogramName, WouldLoadAbove, 1);
+  histogramTester.expectTotalCount(kHistogramName, 2);
+}
+
+TEST_F(DeferredLoadingTest, ZeroByZero) {
+  HistogramTester histogramTester;
+  std::unique_ptr<SimRequest> mainResource = createMainResource();
+
+  mainResource->complete(
+      "<iframe style='height:0px;width:0px;' sandbox></iframe>");
+
+  compositeFrame();
+
+  histogramTester.expectBucketCount(kHistogramName, Created, 1);
+  histogramTester.expectBucketCount(kHistogramName, WouldLoadZeroByZero, 1);
+}
+
+TEST_F(DeferredLoadingTest, DisplayNone) {
+  HistogramTester histogramTester;
+  std::unique_ptr<SimRequest> mainResource = createMainResource();
+
+  mainResource->complete("<iframe style='display:none' sandbox></iframe>");
+
+  compositeFrame();
+
+  histogramTester.expectBucketCount(kHistogramName, Created, 1);
+  histogramTester.expectBucketCount(kHistogramName, WouldLoadDisplayNone, 1);
+}
+
+TEST_F(DeferredLoadingTest, VisibleNestedInRight) {
+  HistogramTester histogramTester;
+  std::unique_ptr<SimRequest> mainResource = createMainResource();
+  SimRequest frameResource("https://example.com/iframe.html", "text/html");
+
+  mainResource->complete(
+      "<iframe style='position:absolute; left:105vw;' src='iframe.html' "
+      "sandbox></iframe>");
+  frameResource.complete("<iframe sandbox></iframe>");
+
+  compositeFrame();
+
+  histogramTester.expectBucketCount(kHistogramName, Created, 2);
+  histogramTester.expectTotalCount(kHistogramName, 2);
+}
+
+TEST_F(DeferredLoadingTest, LeftNestedInBelow) {
+  HistogramTester histogramTester;
+  std::unique_ptr<SimRequest> mainResource = createMainResource();
+  SimRequest frameResource("https://example.com/iframe.html", "text/html");
+
+  mainResource->complete(
+      "<iframe style='position:absolute; top:105vh;' src='iframe.html' "
+      "sandbox></iframe>");
+  frameResource.complete(
+      "<iframe style='position:absolute; left:-10000px;' sandbox></iframe>");
+
+  compositeFrame();
+
+  histogramTester.expectBucketCount(kHistogramName, Created, 2);
+  histogramTester.expectTotalCount(kHistogramName, 2);
+}
+
+TEST_F(DeferredLoadingTest, SameOriginNotCounted) {
+  HistogramTester histogramTester;
+  std::unique_ptr<SimRequest> mainResource = createMainResource();
+  SimRequest frameResource("https://example.com/iframe.html", "text/html");
+
+  mainResource->complete("<iframe src='iframe.html'></iframe>");
+  frameResource.complete("<iframe></iframe>");
+  compositeFrame();
+
+  histogramTester.expectTotalCount(kHistogramName, 0);
+}
+
+}  // namespace blink