Refactor ParseArrayGeometry to use standard Chromium facilities.

content/public/common/content_switches.cc

Index: content/public/common/content_switches.cc
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index af1220672a36a62c4367258cfd3d74e20cda9798..89d973014e0a288be5ca40dc35a0b288315b5112 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -595,6 +595,20 @@ const char kMaxUntiledLayerWidth[]          = "max-untiled-layer-width";
 // Renderer.Memory histogram. Used in memory tests.
 const char kMemoryMetrics[]                 = "memory-metrics";
 
+// Whitespace-separated microphone positions using Cartesian coordinates in
+// meters with ordering x, y, z.
+// x: the horizontal dimension, with positive to the right from the camera's
+//    perspective.
+// y: the depth dimension, with positive forward from the camera's perspective.
+// z: the vertical dimension, with positive upwards.
+//
+// Usually, the center of the microphone array will be treated as the origin
+// (often the position of the camera). The string is formatted as:
+// "x1 y1 z1 ... zn yn zn" for an n-microphone array.
+// For example, a two-mic device with 4 cm of horizontal spacing would use:
+// --mic-positions="-0.02 0 0 0.02 0 0"
+const char kMicrophonePositions[]           = "mic-positions";
+
 // Mutes audio sent to the audio device so it is not audible during
 // automated testing.
 const char kMuteAudio[]                     = "mute-audio";