base: Remove the string logging from CHECK().

ppapi/shared_impl/media_stream_buffer_manager.cc

Index: ppapi/shared_impl/media_stream_buffer_manager.cc
diff --git a/ppapi/shared_impl/media_stream_buffer_manager.cc b/ppapi/shared_impl/media_stream_buffer_manager.cc
index b828c702363b407768935ee9b400911f5cb29429..43d5c2ca2a4e581c3ff95d90e6f6444db7457892 100644
--- a/ppapi/shared_impl/media_stream_buffer_manager.cc
+++ b/ppapi/shared_impl/media_stream_buffer_manager.cc
@@ -71,8 +71,10 @@ std::vector<int32_t> MediaStreamBufferManager::DequeueBuffers() {
 }
 
 void MediaStreamBufferManager::EnqueueBuffer(int32_t index) {
-  CHECK_GE(index, 0) << "Invalid buffer index";
-  CHECK_LT(index, number_of_buffers_) << "Invalid buffer index";
+  // Invalid buffer index
+  CHECK_GE(index, 0);
+  // Invalid buffer index
+  CHECK_LT(index, number_of_buffers_);
   buffer_queue_.push_back(index);
   delegate_->OnNewBufferEnqueued();
 }