Add a histogram for renderer memory usage.

content/browser/renderer_host/render_process_host_impl.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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 800 matching lines @@
     switches::kForceDeviceScaleFactor,
     switches::kFullMemoryCrashReport,
 #if !defined (GOOGLE_CHROME_BUILD)
     // These are unsupported and not fully tested modes, so don't enable them
     // for official Google Chrome builds.
     switches::kInProcessPlugins,
 #endif  // GOOGLE_CHROME_BUILD
     switches::kInProcessWebGL,
     switches::kJavaScriptFlags,
     switches::kLoggingLevel,
+    switches::kMemoryMetrics,
 #if defined(OS_ANDROID)
     switches::kMediaPlayerInRenderProcess,
     switches::kNetworkCountryIso,
 #endif
     switches::kNoReferrers,
     switches::kNoSandbox,
     switches::kOldCheckboxStyle,
     switches::kPpapiOutOfProcess,
     switches::kRegisterPepperPlugins,
     switches::kRendererAssertTest,
@@ skipping 780 matching lines @@
   TRACE_EVENT0("renderer_host",
                "RenderWidgetHostImpl::OnCompositorSurfaceBuffersSwappedNoHost");
   AcceleratedSurfaceMsg_BufferPresented_Params ack_params;
   ack_params.sync_point = 0;
   RenderWidgetHostImpl::AcknowledgeBufferPresent(route_id,
                                                  gpu_process_host_id,
                                                  ack_params);
 }
 
 }  // namespace content