[Chromecast] Implement new volume control API

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"
+#include "base/strings/string_number_conversions.h"
 
 namespace switches {
 
 // 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";
 
 // Server url to upload crash data to.
@@ skipping 45 matching lines @@
 // remain. Assumed to be 0 if --accept-resource-provider is present.
 const char kAlsaCheckCloseTimeout[] = "alsa-check-close-timeout";
 
 // Flag that enables resampling audio with sample rate below 32kHz up to 48kHz.
 // Should be set to true for internal audio products.
 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
 // unavailable.  If this switch is not used, a simple pressure heuristic based
 // purely on free memory will be used.
 const char kMemPressureSystemReservedKb[] = "mem-pressure-system-reserved-kb";
 
 // Used to pass initial screen resolution to GPU process.  This allows us to set
 // screen size correctly (so no need to resize when first window is created).
 const char kCastInitialScreenWidth[] = "cast-initial-screen-width";
@@ skipping 21 matching lines @@
                    << command_line->GetSwitchValueASCII(switch_string)
                    << "; assuming default value of " << default_value;
       return default_value;
     }
     return command_line->GetSwitchValueASCII(switch_string) !=
            switches::kSwitchValueFalse;
   }
   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