Fix CaptureMjpeg test may fail on devices that cannot capture MJPEG.

media/video/capture/video_capture_device_unittest.cc

Index: media/video/capture/video_capture_device_unittest.cc
diff --git a/media/video/capture/video_capture_device_unittest.cc b/media/video/capture/video_capture_device_unittest.cc
index 1742b9fb51eea638ff43b4fc7faf3b6f93aba613..011285c68c21020b259de7559d0448a07df6b447 100644
--- a/media/video/capture/video_capture_device_unittest.cc
+++ b/media/video/capture/video_capture_device_unittest.cc
@@ -128,6 +128,32 @@ class VideoCaptureDeviceTest : public testing::Test {
 
   const VideoCaptureFormat& last_format() const { return last_format_; }
 
+  scoped_ptr<VideoCaptureDevice::Name> GetRquestedPixelFormatDeviceName(

[Ami GONE FROM CHROMIUM, 2014/04/07 17:14:17]

typo: GetRquestedPixelFormatDeviceName

[Ami GONE FROM CHROMIUM, 2014/04/07 17:14:17]

This function's name is a bit convoluted, and "requested" doesn't seem to be
adding value.  WDYT of GetFirstDeviceNameSupportingPixelFormat() and
"pixel_format" for the param?

[yuli, 2014/04/08 07:42:54]

Done.

+      const VideoPixelFormat& requested_pixel_format) {
+    VideoCaptureDevice::GetDeviceNames(&names_);
+    if (!names_.size()) {
+      DVLOG(1) << "No camera available.";
+      return scoped_ptr<VideoCaptureDevice::Name>();
+    }
+    VideoCaptureFormats supported_formats;
+    VideoCaptureDevice::Names::iterator names_iterator;
+    for (names_iterator = names_.begin(); names_iterator != names_.end();
+         ++names_iterator) {
+      VideoCaptureDevice::GetDeviceSupportedFormats(*names_iterator,

[Ami GONE FROM CHROMIUM, 2014/04/07 17:14:17]

This doesn't specify that it clears its output argument, so you should move
l.138 to l.142 (inside the loop) or else clear it explicitly).

[yuli, 2014/04/08 07:42:54]

Done.

+                                                    &supported_formats);
+      VideoCaptureFormats::iterator formats_iterator;
+      for (formats_iterator = supported_formats.begin();
+           formats_iterator != supported_formats.end(); ++formats_iterator) {
+        if (formats_iterator->pixel_format == requested_pixel_format) {
+          return scoped_ptr<VideoCaptureDevice::Name>(
+              new VideoCaptureDevice::Name(*names_iterator));
+        }
+      }
+    }
+    DVLOG(1) << "No camera can capture the requested pixel format.";

[Ami GONE FROM CHROMIUM, 2014/04/07 17:14:17]

DVLOG(1) << "No camera can capture " << requested_pixel_format;

[yuli, 2014/04/08 07:42:54]

Done.

+    return scoped_ptr<VideoCaptureDevice::Name>();
+  }
+
 #if defined(OS_WIN)
   base::win::ScopedCOMInitializer initialize_com_;
 #endif
@@ -332,13 +358,13 @@ TEST_F(VideoCaptureDeviceTest, FakeCapture) {
 
 // Start the camera in 720p to capture MJPEG instead of a raw format.
 TEST_F(VideoCaptureDeviceTest, MAYBE_CaptureMjpeg) {
-  VideoCaptureDevice::GetDeviceNames(&names_);
-  if (!names_.size()) {
-    DVLOG(1) << "No camera available. Exiting test.";
+  scoped_ptr<VideoCaptureDevice::Name> name = GetRquestedPixelFormatDeviceName(
+      PIXEL_FORMAT_MJPEG);
+  if (name.get() == NULL) {
+    DVLOG(1) << "No camera supports MJPEG format. Exiting test.";
     return;
   }
-  scoped_ptr<VideoCaptureDevice> device(
-      VideoCaptureDevice::Create(names_.front()));
+  scoped_ptr<VideoCaptureDevice> device(VideoCaptureDevice::Create(*name));
   ASSERT_TRUE(device.get() != NULL);
 
   EXPECT_CALL(*client_, OnErr())
@@ -359,19 +385,13 @@ TEST_F(VideoCaptureDeviceTest, MAYBE_CaptureMjpeg) {
 }
 
 TEST_F(VideoCaptureDeviceTest, GetDeviceSupportedFormats) {
-  VideoCaptureDevice::GetDeviceNames(&names_);
-  if (!names_.size()) {
-    DVLOG(1) << "No camera available. Exiting test.";
-    return;
-  }
-  VideoCaptureFormats supported_formats;
-  VideoCaptureDevice::Names::iterator names_iterator;
-  for (names_iterator = names_.begin(); names_iterator != names_.end();
-       ++names_iterator) {
-    VideoCaptureDevice::GetDeviceSupportedFormats(*names_iterator,
-                                                  &supported_formats);
-    // Nothing to test here since we cannot forecast the hardware capabilities.
-  }
+  // Use PIXEL_FORMAT_MAX to iterate all device names for testing
+  // GetDeviceSupportedFormats().
+  scoped_ptr<VideoCaptureDevice::Name> name = GetRquestedPixelFormatDeviceName(
+      PIXEL_FORMAT_MAX);
+  // Verify no camera returned for PIXEL_FORMAT_MAX. Nothing else to test here
+  // since we cannot forecast the hardware capabilities.
+  ASSERT_TRUE(name.get() == NULL);
 }
 
 TEST_F(VideoCaptureDeviceTest, FakeCaptureVariableResolution) {