diff --git a/build/gyp.mozbuild b/build/gyp.mozbuild
index e9a6064564be..001cce6cd084 100644
--- a/build/gyp.mozbuild
+++ b/build/gyp.mozbuild
@@ -43,7 +43,7 @@ gyp_vars = {
     # (for vp8) chromium sets to 0 also
     'use_temporal_layers': 0,
     # Creates AEC internal sample dump files in current directory
-    # 'aec_debug_dump': 1,
+    'aec_debug_dump': 1,
 
     # codec enable/disables:
     'include_g711': 1,
diff --git a/media/webrtc/trunk/webrtc/modules/audio_processing/aec/aec_core.c b/media/webrtc/trunk/webrtc/modules/audio_processing/aec/aec_core.c
index 7dda551f3d85..222dcb96b3f3 100644
--- a/media/webrtc/trunk/webrtc/modules/audio_processing/aec/aec_core.c
+++ b/media/webrtc/trunk/webrtc/modules/audio_processing/aec/aec_core.c
@@ -28,6 +28,11 @@
 #include "webrtc/system_wrappers/interface/cpu_features_wrapper.h"
 #include "webrtc/typedefs.h"
 
+extern int AECDebug();
+extern uint32_t AECDebugMaxSize();
+extern void AECDebugEnable(uint32_t enable);
+static void OpenCoreDebugFiles(AecCore* aec, int *instance_count);
+
 // Buffer size (samples)
 static const size_t kBufSizePartitions = 250;  // 1 second of audio in 16 kHz.
 
@@ -211,17 +216,9 @@ int WebRtcAec_CreateAec(AecCore** aecInst) {
     aec = NULL;
     return -1;
   }
-  {
-    char filename[64];
-    sprintf(filename, "aec_far%d.pcm", webrtc_aec_instance_count);
-    aec->farFile = fopen(filename, "wb");
-    sprintf(filename, "aec_near%d.pcm", webrtc_aec_instance_count);
-    aec->nearFile = fopen(filename, "wb");
-    sprintf(filename, "aec_out%d.pcm", webrtc_aec_instance_count);
-    aec->outFile = fopen(filename, "wb");
-    sprintf(filename, "aec_out_linear%d.pcm", webrtc_aec_instance_count);
-    aec->outLinearFile = fopen(filename, "wb");
-  }
+  aec->outLinearFile = aec->outFile = aec->nearFile = aec->farFile = NULL;
+  aec->debugWritten = 0;
+  OpenCoreDebugFiles(aec, &webrtc_aec_instance_count);
 #endif
   aec->delay_estimator_farend =
       WebRtc_CreateDelayEstimatorFarend(PART_LEN1, kHistorySizeBlocks);
@@ -256,10 +253,13 @@ int WebRtcAec_FreeAec(AecCore* aec) {
   WebRtc_FreeBuffer(aec->far_buf_windowed);
 #ifdef WEBRTC_AEC_DEBUG_DUMP
   WebRtc_FreeBuffer(aec->far_time_buf);
-  fclose(aec->farFile);
-  fclose(aec->nearFile);
-  fclose(aec->outFile);
-  fclose(aec->outLinearFile);
+  if (aec->farFile) {
+    // we don't let one be open and not the others
+    fclose(aec->farFile);
+    fclose(aec->nearFile);
+    fclose(aec->outFile);
+    fclose(aec->outLinearFile);
+  }
 #endif
   WebRtc_FreeDelayEstimator(aec->delay_estimator);
   WebRtc_FreeDelayEstimatorFarend(aec->delay_estimator_farend);
@@ -848,8 +848,15 @@ static void ProcessBlock(AecCore* aec) {
     int16_t farend[PART_LEN];
     int16_t* farend_ptr = NULL;
     WebRtc_ReadBuffer(aec->far_time_buf, (void**)&farend_ptr, farend, 1);
-    (void)fwrite(farend_ptr, sizeof(int16_t), PART_LEN, aec->farFile);
-    (void)fwrite(nearend_ptr, sizeof(int16_t), PART_LEN, aec->nearFile);
+    OpenCoreDebugFiles(aec, &webrtc_aec_instance_count);
+    if (aec->farFile) {
+      (void)fwrite(farend_ptr, sizeof(int16_t), PART_LEN, aec->farFile);
+      (void)fwrite(nearend_ptr, sizeof(int16_t), PART_LEN, aec->nearFile);
+      aec->debugWritten += sizeof(int16_t) * PART_LEN;
+      if (aec->debugWritten >= AECDebugMaxSize()) {
+        AECDebugEnable(0);
+      }
+    }
   }
 #endif
 
@@ -1006,8 +1013,11 @@ static void ProcessBlock(AecCore* aec) {
           WEBRTC_SPL_WORD16_MAX, e[i], WEBRTC_SPL_WORD16_MIN);
     }
 
-    (void)fwrite(eInt16, sizeof(int16_t), PART_LEN, aec->outLinearFile);
-    (void)fwrite(output, sizeof(int16_t), PART_LEN, aec->outFile);
+    OpenCoreDebugFiles(aec, &webrtc_aec_instance_count);
+    if (aec->outLinearFile) {
+      (void)fwrite(eInt16, sizeof(int16_t), PART_LEN, aec->outLinearFile);
+      (void)fwrite(output, sizeof(int16_t), PART_LEN, aec->outFile);
+    }
   }
 #endif
 }
@@ -1711,3 +1721,47 @@ static void TimeToFrequency(float time_data[PART_LEN2],
   }
 }
 
+#ifdef WEBRTC_AEC_DEBUG_DUMP
+static void
+OpenCoreDebugFiles(AecCore* aec,
+                   int *instance_count)
+{
+  int error = 0;
+  // XXX  If this impacts performance (opening files here), move file open
+  // to Trace::set_aec_debug(), and just grab them here
+  if (AECDebug() && !aec->farFile) {
+    char filename[128];
+    if (!aec->farFile) {
+      sprintf(filename, "aec_far%d.pcm", webrtc_aec_instance_count);
+      aec->farFile = fopen(filename, "wb");
+      sprintf(filename, "aec_near%d.pcm", webrtc_aec_instance_count);
+      aec->nearFile = fopen(filename, "wb");
+      sprintf(filename, "aec_out%d.pcm", webrtc_aec_instance_count);
+      aec->outFile = fopen(filename, "wb");
+      sprintf(filename, "aec_out_linear%d.pcm", webrtc_aec_instance_count);
+      aec->outLinearFile = fopen(filename, "wb");
+      aec->debugWritten = 0;
+      if (!aec->outLinearFile || !aec->outFile || !aec->nearFile || !aec->farFile) {
+        error = 1;
+      }
+    }
+  }
+  if (error ||
+      (!AECDebug() && aec->farFile)) {
+    if (aec->farFile) {
+      fclose(aec->farFile);
+    }
+    if (aec->nearFile) {
+      fclose(aec->nearFile);
+    }
+    if (aec->outFile) {
+      fclose(aec->outFile);
+    }
+    if (aec->outLinearFile) {
+      fclose(aec->outLinearFile);
+    }
+    aec->outLinearFile = aec->outFile = aec->nearFile = aec->farFile = NULL;
+    aec->debugWritten = 0;
+  }
+}
+#endif
diff --git a/media/webrtc/trunk/webrtc/modules/audio_processing/aec/aec_core_internal.h b/media/webrtc/trunk/webrtc/modules/audio_processing/aec/aec_core_internal.h
index 193369382ca0..8655d47cd80f 100644
--- a/media/webrtc/trunk/webrtc/modules/audio_processing/aec/aec_core_internal.h
+++ b/media/webrtc/trunk/webrtc/modules/audio_processing/aec/aec_core_internal.h
@@ -133,6 +133,7 @@ struct AecCore {
   FILE* nearFile;
   FILE* outFile;
   FILE* outLinearFile;
+  uint32_t debugWritten;
 #endif
 };
 
diff --git a/media/webrtc/trunk/webrtc/modules/audio_processing/aec/echo_cancellation.c b/media/webrtc/trunk/webrtc/modules/audio_processing/aec/echo_cancellation.c
index bbdd5f628b23..3b99154315ea 100644
--- a/media/webrtc/trunk/webrtc/modules/audio_processing/aec/echo_cancellation.c
+++ b/media/webrtc/trunk/webrtc/modules/audio_processing/aec/echo_cancellation.c
@@ -27,6 +27,11 @@
 #include "webrtc/modules/audio_processing/utility/ring_buffer.h"
 #include "webrtc/typedefs.h"
 
+extern int AECDebug();
+extern uint32_t AECDebugMaxSize();
+extern void AECDebugEnable(uint32_t enable);
+static void OpenDebugFiles(aecpc_t* aecpc, int *instance_count);
+
 // Measured delays [ms]
 // Device                Chrome  GTP
 // MacBook Air           10
@@ -165,16 +170,9 @@ int32_t WebRtcAec_Create(void** aecInst) {
     aecpc = NULL;
     return -1;
   }
-  {
-    char filename[64];
-    sprintf(filename, "aec_buf%d.dat", webrtc_aec_instance_count);
-    aecpc->bufFile = fopen(filename, "wb");
-    sprintf(filename, "aec_skew%d.dat", webrtc_aec_instance_count);
-    aecpc->skewFile = fopen(filename, "wb");
-    sprintf(filename, "aec_delay%d.dat", webrtc_aec_instance_count);
-    aecpc->delayFile = fopen(filename, "wb");
-    webrtc_aec_instance_count++;
-  }
+  aecpc->bufFile = aecpc->skewFile = aecpc->delayFile = NULL;
+  OpenDebugFiles(aecpc, &webrtc_aec_instance_count);
+
 #endif
 
   return 0;
@@ -191,9 +189,12 @@ int32_t WebRtcAec_Free(void* aecInst) {
 
 #ifdef WEBRTC_AEC_DEBUG_DUMP
   WebRtc_FreeBuffer(aecpc->far_pre_buf_s16);
-  fclose(aecpc->bufFile);
-  fclose(aecpc->skewFile);
-  fclose(aecpc->delayFile);
+  if (aecpc->bufFile) {
+    // we don't let one be open and not the others
+    fclose(aecpc->bufFile);
+    fclose(aecpc->skewFile);
+    fclose(aecpc->delayFile);
+  }
 #endif
 
   WebRtcAec_FreeAec(aecpc->aec);
@@ -439,9 +440,12 @@ int32_t WebRtcAec_Process(void* aecInst,
   {
     int16_t far_buf_size_ms = (int16_t)(WebRtcAec_system_delay(aecpc->aec) /
                                         (sampMsNb * aecpc->rate_factor));
-    (void)fwrite(&far_buf_size_ms, 2, 1, aecpc->bufFile);
-    (void)fwrite(
+    OpenDebugFiles(aecpc, &webrtc_aec_instance_count);
+    if (aecpc->bufFile) {
+      (void)fwrite(&far_buf_size_ms, 2, 1, aecpc->bufFile);
+      (void)fwrite(
         &aecpc->knownDelay, sizeof(aecpc->knownDelay), 1, aecpc->delayFile);
+    }
   }
 #endif
 
@@ -678,7 +682,10 @@ static int ProcessNormal(aecpc_t* aecpc,
       }
 
 #ifdef WEBRTC_AEC_DEBUG_DUMP
-      (void)fwrite(&aecpc->skew, sizeof(aecpc->skew), 1, aecpc->skewFile);
+      OpenDebugFiles(aecpc, &webrtc_aec_instance_count);
+      if (aecpc->skewFile) {
+        (void)fwrite(&aecpc->skew, sizeof(aecpc->skew), 1, aecpc->skewFile);
+      }
 #endif
     }
   }
@@ -968,3 +975,43 @@ static void EstBufDelayExtended(aecpc_t* self) {
     self->knownDelay = WEBRTC_SPL_MAX((int)self->filtDelay - 256, 0);
   }
 }
+
+#ifdef WEBRTC_AEC_DEBUG_DUMP
+static void
+OpenDebugFiles(aecpc_t* aecpc,
+               int *instance_count)
+{
+  int error = 0;
+  // XXX  If this impacts performance (opening files here), move file open
+  // to Trace::set_aec_debug(), and just grab them here
+  if (AECDebug() && !aecpc->bufFile) {
+    char filename[128];
+    sprintf(filename, "aec_buf%d.dat", *instance_count);
+    aecpc->bufFile = fopen(filename, "wb");
+    sprintf(filename, "aec_skew%d.dat", *instance_count);
+    aecpc->skewFile = fopen(filename, "wb");
+    sprintf(filename, "aec_delay%d.dat", *instance_count);
+    aecpc->delayFile = fopen(filename, "wb");
+
+    if (!aecpc->bufFile || !aecpc->skewFile || !aecpc->delayFile) {
+      error = 1;
+    } else {
+      (*instance_count)++;
+    }
+  }
+  if (error ||
+      (!AECDebug() && aecpc->bufFile)) {
+    if (aecpc->bufFile) {
+      fclose(aecpc->bufFile);
+    }
+    if (aecpc->skewFile) {
+      fclose(aecpc->skewFile);
+    }
+    if (aecpc->delayFile) {
+      fclose(aecpc->delayFile);
+    }
+    aecpc->bufFile = aecpc->skewFile = aecpc->delayFile = NULL;
+  }
+}
+
+#endif
diff --git a/media/webrtc/trunk/webrtc/system_wrappers/interface/trace.h b/media/webrtc/trunk/webrtc/system_wrappers/interface/trace.h
index 44ea658bdf28..9085680b537f 100644
--- a/media/webrtc/trunk/webrtc/system_wrappers/interface/trace.h
+++ b/media/webrtc/trunk/webrtc/system_wrappers/interface/trace.h
@@ -54,6 +54,12 @@ class Trace {
   // Returns what type of messages are written to the trace file.
   static uint32_t level_filter() { return level_filter_; }
 
+  // Enable dumping of AEC inputs and outputs.  Can be changed in mid-call
+  static void set_aec_debug(bool enable) { aec_debug_ = enable; }
+  static void set_aec_debug_size(uint32_t size) { aec_debug_size_ = size; }
+  static bool aec_debug() { return aec_debug_; }
+  static uint32_t aec_debug_size() { return aec_debug_size_; }
+
   // Sets the file name. If add_file_counter is false the same file will be
   // reused when it fills up. If it's true a new file with incremented name
   // will be used.
@@ -85,8 +91,16 @@ class Trace {
 
  private:
   static uint32_t level_filter_;
+  static bool aec_debug_;
+  static uint32_t aec_debug_size_;
 };
 
 }  // namespace webrtc
 
+extern "C" {
+  extern int AECDebug();
+  extern uint32_t AECDebugMaxSize();
+  extern void AECDebugEnable(uint32_t enable);
+}
+
 #endif  // WEBRTC_SYSTEM_WRAPPERS_INTERFACE_TRACE_H_
diff --git a/media/webrtc/trunk/webrtc/system_wrappers/source/trace_impl.cc b/media/webrtc/trunk/webrtc/system_wrappers/source/trace_impl.cc
index 73b5b29b0563..f5b05ac4f5f4 100644
--- a/media/webrtc/trunk/webrtc/system_wrappers/source/trace_impl.cc
+++ b/media/webrtc/trunk/webrtc/system_wrappers/source/trace_impl.cc
@@ -29,12 +29,20 @@
 #pragma warning(disable:4355)
 #endif  // _WIN32
 
+extern "C" {
+  int AECDebug() { return (int) webrtc::Trace::aec_debug(); }
+  uint32_t AECDebugMaxSize() { return webrtc::Trace::aec_debug_size(); }
+  void AECDebugEnable(uint32_t enable) { webrtc::Trace::set_aec_debug(!!enable); }
+}
+
 namespace webrtc {
 
 const int Trace::kBoilerplateLength = 71;
 const int Trace::kTimestampPosition = 13;
 const int Trace::kTimestampLength = 12;
 uint32_t Trace::level_filter_ = kTraceDefault;
+bool Trace::aec_debug_ = false;
+uint32_t Trace::aec_debug_size_ = 4*1024*1024;
 
 // Construct On First Use idiom. Avoids "static initialization order fiasco".
 TraceImpl* TraceImpl::StaticInstance(CountOperation count_operation,