Shape Detection: Add two content browser tests for face detection

content/browser/shapedetection/shapedetection_browsertest.cc

+// 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 "base/command_line.h"
+#include "base/strings/string_tokenizer.h"
+#include "content/public/common/content_switches.h"
+#include "content/public/test/browser_test_utils.h"
+#include "content/public/test/content_browser_test.h"
+#include "content/public/test/content_browser_test_utils.h"
+
+namespace content {
+
+// TODO(xianglu): Enable other platforms with support. https://crbug.com/646083
+#if defined(OS_ANDROID)
+#define MAYBE_DetectFacesOnImageWithNoFaces DetectFacesOnImageWithNoFaces
+#define MAYBE_DetectFacesOnImageWithOneFace DetectFacesOnImageWithOneFace
+#else
+#define MAYBE_DetectFacesOnImageWithNoFaces DISABLED_DetectFacesOnImageWithNoFaces
+#define MAYBE_DetectFacesOnImageWithOneFace DISABLED_DetectFacesOnImageWithOneFace
+#endif
+
+namespace {
+
+const char kFaceDetectionTestHtml[] = "/media/face_detection_test.html";
+
+}  // namespace
+
+// This class contains content_browsertests for Shape Detection API, which
+// allows for generating bounding boxes for faces on still images..
+class ShapeDetectionBrowserTest : public ContentBrowserTest {
+ public:
+  void SetUpCommandLine(base::CommandLine* command_line) override {
+    // Specific flag to enable ShapeDetection and DOMRect API.
+    base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+        switches::kEnableBlinkFeatures, "ShapeDetection, GeometryInterfaces");
+  }
+
+ protected:
+  void RunDetectFacesOnImageUrl(
+      const std::string& image_path,
+      const std::vector<std::vector<float>>& expected_results) {
+    ASSERT_TRUE(embedded_test_server()->Start());
+
+    const GURL html_url(embedded_test_server()->GetURL(kFaceDetectionTestHtml));
+    const GURL image_url(embedded_test_server()->GetURL(image_path));
+    NavigateToURL(shell(), html_url);
+    const std::string js_command =
+        "detectFacesOnImageUrl('" + image_url.spec() + "')";
+    std::string response_string;
+    ASSERT_TRUE(
+        ExecuteScriptAndExtractString(shell(), js_command, &response_string));
+
+    base::StringTokenizer outer_tokenizer(response_string, "#");
+    std::vector<std::vector<float>> results;
+    while (outer_tokenizer.GetNext()) {
+      std::string s = outer_tokenizer.token().c_str();
+      std::vector<float> res;
+      base::StringTokenizer inner_tokenizer(s, ",");
+      while (inner_tokenizer.GetNext()) {
+        res.push_back(atof(inner_tokenizer.token().c_str()));
+      }

[mcasas, 2016/10/19 23:41:11]

nit: no need for curly brackets {} for one line bodies.

[xianglu, 2016/10/20 17:58:48]

Done.

+      results.push_back(res);
+    }
+
+    ASSERT_EQ(expected_results.size(), results.size());

[mcasas, 2016/10/19 23:41:11]

Good!

+    for (size_t face_id = 0; face_id < results.size(); face_id++) {
+      std::vector<float> expected_result = expected_results[face_id];
+      std::vector<float> result = results[face_id];
+      for (size_t pram_idx = 0; pram_idx < 4; pram_idx++) {

[mcasas, 2016/10/19 23:41:11]

Micro-nit:  try to get used to preincrement
the index variable in for loops; in this case, it
doesn't matter, but in certain situatiosns, pre and 
post increments are different, and you want the
pre. (This applies to l. 67 and 70).

Also, variable names should not be abbreviations:
|pram_idx| is illegible. What about just |index|, or |i| ?

[xianglu, 2016/10/20 17:58:47]

Done.

+        // TODO(xianglu): Always verify if EXPECT_FLOAT_EQ is sufficient for
+        // different platforms.

[mcasas, 2016/10/19 23:41:11]

You can also consider using e.g.
EXPECT_NEAR(expected_result[pram_idx], result[pram_idx], 0.1),
where 0.1 is the tolerated error, and then it should
work in all platforms (and 0.1 pixels of error in a 
face bounding box is totally cool), and then you don't
need the comment :)

[xianglu, 2016/10/20 17:58:48]

Done.

+        EXPECT_FLOAT_EQ(expected_result[pram_idx], result[pram_idx]);

[Reilly Grant (use Gerrit), 2016/10/19 23:48:40]

Tip: Add << " at index " << param_index; to the end of test expectations like
this because it'll make it easier to debug failures in the future.

[xianglu, 2016/10/20 17:58:48]

Done.

+      }
+    }
+  }
+};
+
+IN_PROC_BROWSER_TEST_F(ShapeDetectionBrowserTest,
+                       MAYBE_DetectFacesOnImageWithNoFaces) {
+  const std::string image_path = "/blank.jpg";
+  std::vector<std::vector<float>> expected_results;
+  RunDetectFacesOnImageUrl(image_path, expected_results);
+}
+
+IN_PROC_BROWSER_TEST_F(ShapeDetectionBrowserTest,
+                       MAYBE_DetectFacesOnImageWithOneFace) {
+  const std::string image_path = "/single_face.jpg";
+  std::vector<float> expected_result = {68.640625, 102.96875, 171.5625,
+                                        171.5625};

[mcasas, 2016/10/19 23:41:11]

nit: const :)

[xianglu, 2016/10/20 17:58:48]

Done.

+  std::vector<std::vector<float>> expected_results = {expected_result};
+  RunDetectFacesOnImageUrl(image_path, expected_results);
+}
+
+}  // namespace content