[Chromecast] Implement new volume control API

chromecast/base/chromecast_switches.cc

Index: chromecast/base/chromecast_switches.cc
diff --git a/chromecast/base/chromecast_switches.cc b/chromecast/base/chromecast_switches.cc
index 426de0c7208b1970dc978d62a6f4e5e374b37ef5..3cd4cf6ba102159ff2f679ae6c3b86ca2f6d05ca 100644
--- a/chromecast/base/chromecast_switches.cc
+++ b/chromecast/base/chromecast_switches.cc
@@ -5,6 +5,7 @@
 #include "chromecast/base/chromecast_switches.h"
 
 #include "base/command_line.h"
+#include "base/strings/string_number_conversions.h"
 
 namespace switches {
 
@@ -70,6 +71,9 @@ const char kAlsaEnableUpsampling[] = "alsa-enable-upsampling";
 // Optional flag to set a fixed sample rate for the alsa device.
 const char kAlsaFixedOutputSampleRate[] = "alsa-fixed-output-sample-rate";
 
+// Calibrated max output volume dBa for voice content at 1 meter, if known.
+const char kMaxOutputVolumeDba1m[] = "max-output-volume-dba1m";
+
 // Some platforms typically have very little 'free' memory, but plenty is
 // available in buffers+cached.  For such platforms, configure this amount
 // as the portion of buffers+cached memory that should be treated as
@@ -111,4 +115,33 @@ bool GetSwitchValueBoolean(const std::string& switch_string,
   return default_value;
 }
 
+int GetSwitchValueInt(const std::string& switch_name, const int default_value) {
+  const base::CommandLine* command_line =
+      base::CommandLine::ForCurrentProcess();
+  if (!command_line->HasSwitch(switch_name)) {
+    return default_value;
+  }
+
+  int arg_value;
+  if (!base::StringToInt(command_line->GetSwitchValueASCII(switch_name),
+                         &arg_value)) {
+    LOG(DFATAL) << "--" << switch_name << " only accepts integers as arguments";
+    return default_value;
+  }
+  return arg_value;
+}
+
+int GetSwitchValueNonNegativeInt(const std::string& switch_name,
+                                 const int default_value) {
+  DCHECK_GE(default_value, 0)
+      << "--" << switch_name << " must have a non-negative default value";
+
+  int value = GetSwitchValueInt(switch_name, default_value);
+  if (value < 0) {
+    LOG(DFATAL) << "--" << switch_name << " must have a non-negative value";
+    return default_value;
+  }
+  return value;
+}
+
 }  // namespace chromecast