Per-host V8 histograms.

content/renderer/render_thread_impl_unittest.cc

+// Copyright (c) 2012 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 "content/renderer/render_thread_impl.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+#include <string>
+
+class RenderThreadImplUnittest : public testing::Test {
+ public:
+  RenderThreadImplUnittest()
+      : kCustomizableHistogram_("Histogram1"),
+        kNormalHistogram_("Histogram2") {}
+  ~RenderThreadImplUnittest() {}
+ protected:
+  virtual void SetUp() OVERRIDE {
+    histogram_customizer_.custom_histograms_.clear();
+    histogram_customizer_.custom_histograms_.insert(kCustomizableHistogram_);
+  }
+  RenderThreadImpl::HistogramCustomizer histogram_customizer_;
+  const char* kCustomizableHistogram_;
+  const char* kNormalHistogram_;
+};
+
+TEST_F(RenderThreadImplUnittest, CustomHistogramsWithNoNavigations) {
+  // First there is no page -> no custom histograms.
+  EXPECT_EQ(kCustomizableHistogram_,
+            histogram_customizer_.ConvertToCustomHistogramName(
+                kCustomizableHistogram_));
+  EXPECT_EQ(kNormalHistogram_,
+            histogram_customizer_.ConvertToCustomHistogramName(
+                kNormalHistogram_));
+}
+
+TEST_F(RenderThreadImplUnittest, CustomHistogramsForOneRenderView) {
+  histogram_customizer_.RenderViewNavigatedToHost("mail.google.com", 1);
+  EXPECT_EQ(std::string(kCustomizableHistogram_) + ".gmail",
+            histogram_customizer_.ConvertToCustomHistogramName(
+                kCustomizableHistogram_));
+  EXPECT_EQ(kNormalHistogram_,
+            histogram_customizer_.ConvertToCustomHistogramName(
+                kNormalHistogram_));
+  histogram_customizer_.RenderViewNavigatedToHost("docs.google.com", 1);
+  EXPECT_EQ(std::string(kCustomizableHistogram_) + ".docs",
+            histogram_customizer_.ConvertToCustomHistogramName(
+                kCustomizableHistogram_));
+  histogram_customizer_.RenderViewNavigatedToHost("nottracked.com", 1);
+  EXPECT_EQ(kCustomizableHistogram_,
+            histogram_customizer_.ConvertToCustomHistogramName(
+                kCustomizableHistogram_));
+}
+
+TEST_F(RenderThreadImplUnittest, CustomHistogramsForTwoRenderViews) {
+  // First there is only one view.
+  histogram_customizer_.RenderViewNavigatedToHost("mail.google.com", 1);
+  // Second view created and it navigates to the same host -> we can have a
+  // custom diagram.
+  histogram_customizer_.RenderViewNavigatedToHost("mail.google.com", 2);
+  EXPECT_EQ(std::string(kCustomizableHistogram_) + ".gmail",
+            histogram_customizer_.ConvertToCustomHistogramName(
+                kCustomizableHistogram_));
+  EXPECT_EQ(kNormalHistogram_,
+            histogram_customizer_.ConvertToCustomHistogramName(
+                kNormalHistogram_));
+  // Now the views diverge (one of them navigates to a different host) -> no
+  // custom diagram.
+  histogram_customizer_.RenderViewNavigatedToHost("docs.google.com", 2);
+  EXPECT_EQ(kCustomizableHistogram_,
+            histogram_customizer_.ConvertToCustomHistogramName(
+                kCustomizableHistogram_));
+  // After this point, there will never be a custom diagram again, even if the
+  // view navigated back to the common host.
+  histogram_customizer_.RenderViewNavigatedToHost("mail.google.com", 2);
+  EXPECT_EQ(kCustomizableHistogram_,
+            histogram_customizer_.ConvertToCustomHistogramName(
+                kCustomizableHistogram_));
+}