Revert 264647

content/browser/renderer_host/media/audio_input_renderer_host.cc

Index: content/browser/renderer_host/media/audio_input_renderer_host.cc
===================================================================
--- content/browser/renderer_host/media/audio_input_renderer_host.cc	(revision 264794)
+++ content/browser/renderer_host/media/audio_input_renderer_host.cc	(working copy)
@@ -7,7 +7,6 @@
 #include "base/bind.h"
 #include "base/memory/shared_memory.h"
 #include "base/metrics/histogram.h"
-#include "base/numerics/safe_math.h"
 #include "base/process/process.h"
 #include "base/strings/stringprintf.h"
 #include "content/browser/media/media_internals.h"
@@ -259,10 +258,8 @@
 
   // Create the shared memory and share it with the renderer process
   // using a new SyncWriter object.
-  base::CheckedNumeric<uint32> size = segment_size;
-  size *= entry->shared_memory_segment_count;
-  if (!size.IsValid() ||
-      !entry->shared_memory.CreateAndMapAnonymous(size.ValueOrDie())) {
+  if (!entry->shared_memory.CreateAndMapAnonymous(
+      segment_size * entry->shared_memory_segment_count)) {
     // If creation of shared memory failed then send an error message.
     SendErrorMessage(stream_id, SHARED_MEMORY_CREATE_FAILED);
     return;