Allow FakeVideoCaptureDeviceFactory to specify number of supported formats per device.

media/capture/video/fake_video_capture_device_factory.cc

 // Copyright 2014 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 "media/capture/video/fake_video_capture_device_factory.h"
 
 #include "base/command_line.h"
+#include "base/macros.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_tokenizer.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "build/build_config.h"
 #include "media/base/media_switches.h"
 
 namespace {
 
@@ skipping 11 matching lines @@
 namespace media {
 
 // Cap the frame rate command line input to reasonable values.
 static const float kFakeCaptureMinFrameRate = 5.0f;
 static const float kFakeCaptureMaxFrameRate = 60.0f;
 // Default rate if none is specified as part of the command line.
 static const float kFakeCaptureDefaultFrameRate = 20.0f;
 // Cap the device count command line input to reasonable values.
 static const int kFakeCaptureMinDeviceCount = 1;
 static const int kFakeCaptureMaxDeviceCount = 10;
+static const int kFakeCaptureMinFormatCount = 0;
 
 FakeVideoCaptureDeviceFactory::FakeVideoCaptureDeviceFactory()
     : number_of_devices_(1),
+      number_of_formats_per_device_(5),
       fake_vcd_ownership_(FakeVideoCaptureDevice::BufferOwnership::OWN_BUFFERS),
       frame_rate_(kFakeCaptureDefaultFrameRate) {}
 
 std::unique_ptr<VideoCaptureDevice> FakeVideoCaptureDeviceFactory::CreateDevice(
     const VideoCaptureDeviceDescriptor& device_descriptor) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   if (!command_line_parsed_) {
     ParseCommandLine();
     command_line_parsed_ = true;
@@ skipping 48 matching lines @@
 }
 
 void FakeVideoCaptureDeviceFactory::GetSupportedFormats(
     const VideoCaptureDeviceDescriptor& device_descriptor,
     VideoCaptureFormats* supported_formats) {
   DCHECK(thread_checker_.CalledOnValidThread());
   const gfx::Size supported_sizes[] = {
       gfx::Size(96, 96), gfx::Size(320, 240), gfx::Size(640, 480),
       gfx::Size(1280, 720), gfx::Size(1920, 1080)};
   supported_formats->clear();
-  for (const auto& size : supported_sizes) {
-    supported_formats->push_back(VideoCaptureFormat(
-        size, frame_rate_, GetPixelFormat(device_descriptor.device_id)));
+  size_t num_formats =
+      std::min(arraysize(supported_sizes),
+               static_cast<size_t>(number_of_formats_per_device_));
+  for (size_t i = 0; i < num_formats; ++i) {
+    supported_formats->push_back(
+        VideoCaptureFormat(supported_sizes[i], frame_rate_,
+                           GetPixelFormat(device_descriptor.device_id)));
   }
 }
 
 // Optional comma delimited parameters to the command line can specify buffer
 // ownership, device count, and the fake video devices FPS.
 // Examples: "ownership=client, device-count=2, fps=60" "fps=30"
 void FakeVideoCaptureDeviceFactory::ParseCommandLine() {
   const std::string option =
       base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
           switches::kUseFakeDeviceForMediaStream);
@@ skipping 23 matching lines @@
         frame_rate_ = std::min(kFakeCaptureMaxFrameRate, frame_rate_);
       }
     } else if (base::EqualsCaseInsensitiveASCII(param.front(),
                                                 "device-count")) {
       unsigned int count = 0;
       if (base::StringToUint(param.back(), &count)) {
         number_of_devices_ = std::min(
             kFakeCaptureMaxDeviceCount,
             std::max(kFakeCaptureMinDeviceCount, static_cast<int>(count)));
       }
+    } else if (base::EqualsCaseInsensitiveASCII(param.front(),
+                                                "format-count")) {
+      unsigned int count = 0;
+      if (base::StringToUint(param.back(), &count)) {
+        number_of_formats_per_device_ =
+            std::max(kFakeCaptureMinFormatCount, static_cast<int>(count));
+      }

[mcasas, 2017/02/14 17:01:01]

I think adding a new command line flag and member variable
is overkill just for a unittest (media_devices_dispatcher_host_unittest.cc).

Can we do it some other way? E.g. by adding a new
ReturnNoEnumeratedFormatsForTesting() to FakeVCDFactory ?

     }
   }
 }
 
 }  // namespace media