Remove the majority of the high-traffic Net.Async* histograms.

content/browser/loader/async_resource_handler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/loader/async_resource_handler.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/containers/hash_tables.h"
 #include "base/debug/alias.h"
 #include "base/logging.h"
 #include "base/memory/shared_memory.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/time/time.h"
 #include "content/browser/devtools/devtools_netlog_observer.h"
 #include "content/browser/host_zoom_map_impl.h"
 #include "content/browser/loader/resource_buffer.h"
 #include "content/browser/loader/resource_dispatcher_host_impl.h"
 #include "content/browser/loader/resource_message_filter.h"
 #include "content/browser/loader/resource_request_info_impl.h"
 #include "content/browser/resource_context_impl.h"
 #include "content/common/resource_messages.h"
@@ skipping 26 matching lines @@
   static bool did_init = false;
   if (did_init)
     return;
   did_init = true;
 
   GetNumericArg("resource-buffer-size", &kBufferSize);
   GetNumericArg("resource-buffer-min-allocation-size", &kMinAllocationSize);
   GetNumericArg("resource-buffer-max-allocation-size", &kMaxAllocationSize);
 }
 
-int CalcUsedPercentage(int bytes_read, int buffer_size) {
-  double ratio = static_cast<double>(bytes_read) / buffer_size;
-  return static_cast<int>(ratio * 100.0 + 0.5);  // Round to nearest integer.
-}
-
 }  // namespace
 
 class DependentIOBuffer : public net::WrappedIOBuffer {
  public:
   DependentIOBuffer(ResourceBuffer* backing, char* memory)
       : net::WrappedIOBuffer(memory),
         backing_(backing) {
   }
  private:
   ~DependentIOBuffer() override {}
@@ skipping 172 matching lines @@
   if (!EnsureResourceBufferIsInitialized())
     return false;
 
   DCHECK(buffer_->CanAllocate());
   char* memory = buffer_->Allocate(&allocation_size_);
   CHECK(memory);
 
   *buf = new DependentIOBuffer(buffer_.get(), memory);
   *buf_size = allocation_size_;
 
-  UMA_HISTOGRAM_CUSTOM_COUNTS(
-      "Net.AsyncResourceHandler_SharedIOBuffer_Alloc",
-      *buf_size, 0, kMaxAllocationSize, 100);
   return true;
 }
 
 bool AsyncResourceHandler::OnReadCompleted(int bytes_read, bool* defer) {
   DCHECK_GE(bytes_read, 0);
 
   if (!bytes_read)
     return true;
 
   ResourceMessageFilter* filter = GetFilter();
   if (!filter)
     return false;
 
   buffer_->ShrinkLastAllocation(bytes_read);
 
-  UMA_HISTOGRAM_CUSTOM_COUNTS(
-      "Net.AsyncResourceHandler_SharedIOBuffer_Used",
-      bytes_read, 0, kMaxAllocationSize, 100);
-  UMA_HISTOGRAM_PERCENTAGE(
-      "Net.AsyncResourceHandler_SharedIOBuffer_UsedPercentage",
-      CalcUsedPercentage(bytes_read, allocation_size_));
-
   if (!sent_first_data_msg_) {
     base::SharedMemoryHandle handle;
     int size;
     if (!buffer_->ShareToProcess(filter->PeerHandle(), &handle, &size))
       return false;
     filter->Send(new ResourceMsg_SetDataBuffer(
         GetRequestID(), handle, size, filter->peer_pid()));
     sent_first_data_msg_ = true;
   }
 
   int data_offset = buffer_->GetLastAllocationOffset();
 
   int64_t current_transfer_size = request()->GetTotalReceivedBytes();
   int encoded_data_length = current_transfer_size - reported_transfer_size_;
   reported_transfer_size_ = current_transfer_size;
 
   filter->Send(new ResourceMsg_DataReceived(
       GetRequestID(), data_offset, bytes_read, encoded_data_length));
   ++pending_data_count_;
-  UMA_HISTOGRAM_CUSTOM_COUNTS(
-      "Net.AsyncResourceHandler_PendingDataCount",
-      pending_data_count_, 0, 100, 100);
 
   if (!buffer_->CanAllocate()) {
-    UMA_HISTOGRAM_CUSTOM_COUNTS(
-        "Net.AsyncResourceHandler_PendingDataCount_WhenFull",
-        pending_data_count_, 0, 100, 100);
     *defer = did_defer_ = true;
     OnDefer();
   }
 
   return true;
 }
 
 void AsyncResourceHandler::OnDataDownloaded(int bytes_downloaded) {
   int64_t current_transfer_size = request()->GetTotalReceivedBytes();
   int encoded_data_length = current_transfer_size - reported_transfer_size_;
@@ skipping 83 matching lines @@
     request()->LogUnblocked();
     controller()->Resume();
   }
 }
 
 void AsyncResourceHandler::OnDefer() {
   request()->LogBlockedBy("AsyncResourceHandler");
 }
 
 }  // namespace content