Report Android Build.MODEL in SystemProfileProto hardware_class.

components/metrics/proto/system_profile.proto

 // Copyright 2014 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.
 //
 // Stores information about the user's brower and system configuration.
 // The system configuration fields are recorded once per client session.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
@@ skipping 94 matching lines @@
     // The CPU architecture (x86, PowerPC, x86_64, ...)
     optional string cpu_architecture = 1;
 
     // The amount of RAM present on the system, in megabytes.
     optional int64 system_ram_mb = 2;
 
     // The base memory address that chrome.dll was loaded at.
     // (Logged only on Windows.)
     optional int64 dll_base = 3;
 
-    // The Chrome OS device hardware class ID is a unique string associated with
-    // each Chrome OS device product revision generally assigned at hardware
-    // qualification time.  The hardware class effectively identifies the
-    // configured system components such as CPU, WiFi adapter, etc.
+    // The hardware_class describes the current machine model, e.g. "MacPro1,1"

[Alexei Svitkine (slow), 2015/07/21 16:52:11]

Can you also send a CL to update this comment in the internal copy of this
proto? Thanks!

+    // on Mac, or "Nexus 5" on Android. Only implemented on OS X, Android, and
+    // Chrome OS.
+    //
+    // For Chrome OS, the device hardware class ID is a unique string associated
+    // with each Chrome OS device product revision generally assigned at
+    // hardware qualification time. The hardware class effectively identifies
+    // the configured system components such as CPU, WiFi adapter, etc.
     //
     // An example of such a hardware class is "IEC MARIO PONY 6101".  An
     // internal database associates this hardware class with the qualified
     // device specifications including OEM information, schematics, hardware
     // qualification reports, test device tags, etc.
     optional string hardware_class = 4;
 
     // The number of physical screens.
     optional int32 screen_count = 5;
 
@@ skipping 604 matching lines @@
   // then HAS_OFFSTORE is reported. This should be kept in sync with the
   // corresponding enum in chrome/browser/metrics/extensions_metrics_provider.cc
   enum ExtensionsState {
     NO_EXTENSIONS = 0;
     NO_OFFSTORE_VERIFIED = 1;
     NO_OFFSTORE_UNVERIFIED = 2;
     HAS_OFFSTORE = 3;
   }
   optional ExtensionsState offstore_extensions_state = 19;
 }