[chromecast] Add cast_shell --accept-resource-provider switch

chromecast/base/chromecast_switches.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 "chromecast/base/chromecast_switches.h"
 
+#include "base/command_line.h"
+
 namespace switches {
 
+namespace {
+// Value indicating whether flag from command line switch is true.
+const char kSwitchValueTrue[] = "true";
+// Value indicating whether flag from command line switch is false.
+const char kSwitchValueFalse[] = "false";
+}  // namespace
+
 // Enable the CMA media pipeline.
 const char kEnableCmaMediaPipeline[] = "enable-cma-media-pipeline";
 
 // The bitmask of codecs (media_caps.h) supported by the current HDMI sink.
 const char kHdmiSinkSupportedCodecs[] = "hdmi-sink-supported-codecs";
 
 // Enable file accesses. It should not be enabled for most Cast devices.
 const char kEnableLocalFileAccesses[] = "enable-local-file-accesses";
 
 // Override the URL to which metrics logs are sent for debugging.
 const char kOverrideMetricsUploadUrl[] = "override-metrics-upload-url";
 
 // Disable features that require WiFi management.
 const char kNoWifi[] = "no-wifi";
 
 // Allows media playback for hidden WebContents
 const char kAllowHiddenMediaPlayback[] = "allow-hidden-media-playback";
 
 // Pass the app id information to the renderer process, to be used for logging.
 // last-launched-app should be the app that just launched and is spawning the
 // renderer.
 const char kLastLaunchedApp[] = "last-launched-app";
 // previous-app should be the app that was running when last-launched-app
 // started.
 const char kPreviousApp[] = "previous-app";
 
+// Flag indicating that a resource provider must be set up to provide cast
+// receiver with resources. Apps cannot start until provided resources.
+// This flag implies --alsa-check-close-timeout=0.
+const char kAcceptResourceProvider[] = "accept-resource-provider";
+
 // Size of the ALSA output buffer in frames. This directly sets the latency of
 // the output device. Latency can be calculated by multiplying the sample rate
 // by the output buffer size.
 const char kAlsaOutputBufferSize[] = "alsa-output-buffer-size";
 
 // Size of the ALSA output period in frames. The period of an ALSA output device
 // determines how many frames elapse between hardware interrupts.
 const char kAlsaOutputPeriodSize[] = "alsa-output-period-size";
 
 // How many frames need to be in the output buffer before output starts.
 const char kAlsaOutputStartThreshold[] = "alsa-output-start-threshold";
 
 // Minimum number of available frames for scheduling a transfer.
 const char kAlsaOutputAvailMin[] = "alsa-output-avail-min";
 
 // Time in ms to wait before closing the PCM handle when no more mixer inputs
-// remain.
+// remain. Assumed to be 0 if --accept-resource-provider is present.
 const char kAlsaCheckCloseTimeout[] = "alsa-check-close-timeout";
 
 // Number of channels on the alsa output device that the stream mixer uses.
 // Default is 2 channels.
 const char kAlsaNumOutputChannels[] = "alsa-num-output-channels";
 
 }  // namespace switches
+
+namespace cast {
+
+bool GetSwitchValueBoolean(const std::string& switch_string,
+                           const bool default_value) {
+  const base::CommandLine* command_line =
+      base::CommandLine::ForCurrentProcess();
+  bool ret = default_value;
+  if (command_line->HasSwitch(switch_string)) {
+    if (command_line->GetSwitchValueASCII(switch_string)
+            .compare(switches::kSwitchValueTrue) &&

[kmackay, 2016/03/08 17:32:48]

I'd really prefer to use == or != rather than compare() (!= in this case).

[jyw, 2016/03/08 22:40:51]

Done.

+        command_line->GetSwitchValueASCII(switch_string)
+            .compare(switches::kSwitchValueFalse) &&
+        command_line->GetSwitchValueASCII(switch_string).compare("")) {
+      LOG(WARNING) << "Invalid switch value " << switch_string << "="
+                   << command_line->GetSwitchValueASCII(switch_string)
+                   << "; assuming default value of " << default_value;
+      return default_value;
+    }
+    ret = command_line->GetSwitchValueASCII(switch_string)
+              .compare(switches::kSwitchValueFalse);
+  }
+  return ret;
+}
+
+}  // namespace cast