Fix "unused variable" warnings.

media/cast/sender/audio_encoder.cc

Index: media/cast/sender/audio_encoder.cc
diff --git a/media/cast/sender/audio_encoder.cc b/media/cast/sender/audio_encoder.cc
index 1ab31f2cca95023cac7e235fdcaf53955d33ded5..9c6c6f44b5e40e34b0d883f0cc18ab07c0e8be1b 100644
--- a/media/cast/sender/audio_encoder.cc
+++ b/media/cast/sender/audio_encoder.cc
@@ -363,8 +363,7 @@ class AudioEncoder::AppleAacImpl : public AudioEncoder::ImplBase {
         output_buffer_(nullptr),
         converter_(nullptr),
         file_(nullptr),
-        num_access_units_(0),
-        can_resume_(true) {
+        num_access_units_(0) {
     if (ImplBase::operational_status_ != STATUS_UNINITIALIZED) {
       return;
     }
@@ -455,23 +454,6 @@ class AudioEncoder::AppleAacImpl : public AudioEncoder::ImplBase {
       }
     }
 
-#if defined(OS_IOS)
-    // See the comment next to |can_resume_| for details on resumption. Some
-    // converters can return kAudioConverterErr_PropertyNotSupported, in which
-    // case resumption is implicitly supported. This is the only location where
-    // the implementation modifies |can_resume_|.
-    uint32_t can_resume;
-    prop_size = sizeof(can_resume);
-    OSStatus oserr = AudioConverterGetProperty(
-        converter_,
-        kAudioConverterPropertyCanResumeFromInterruption,
-        &prop_size,
-        &can_resume);
-    if (oserr == noErr) {
-      const_cast<bool&>(can_resume_) = can_resume != 0;

[Peter Kasting, 2016/05/19 07:23:29]

This member is never read, and the bug associated with doing anything with it
was WontFixed last year.

[hubbe, 2016/05/19 17:21:41]

Can you point me to the bug in question?

[Peter Kasting, 2016/05/19 18:10:18]

It's the one referred to in the other deleted block below:
https://crbug.com/424787

-    }
-#endif
-
     // Figure out the maximum size of an access unit that the encoder can
     // produce. |mBytesPerPacket| will be 0 for variable size configurations,
     // in which case we must query the value.
@@ -724,16 +706,6 @@ class AudioEncoder::AppleAacImpl : public AudioEncoder::ImplBase {
   // The number of access units emitted so far by the encoder.
   uint64_t num_access_units_;
 
-  // On iOS, audio codecs can be interrupted by other services (such as an
-  // audio alert or phone call). Depending on the underlying hardware and
-  // configuration, the codec may have to be thrown away and re-initialized
-  // after such an interruption. This flag tracks if we can resume or not from
-  // such an interruption. It is initialized to true, which is the only possible
-  // value on OS X and on most modern iOS hardware.
-  // TODO(jfroy): Implement encoder re-initialization after interruption.
-  //              https://crbug.com/424787
-  const bool can_resume_;
-
   DISALLOW_COPY_AND_ASSIGN(AppleAacImpl);
 };
 #endif  // defined(OS_MACOSX)