Add MemoryLeakReportProto enum/field for type of process

components/metrics/proto/memory_leak_report.proto

Index: components/metrics/proto/memory_leak_report.proto
diff --git a/components/metrics/proto/memory_leak_report.proto b/components/metrics/proto/memory_leak_report.proto
index 65a40e5b249886fb0f521e454682bd3aa4dd0358..496cf9fb72ed9317567594e6db7c1cec20988d22 100644
--- a/components/metrics/proto/memory_leak_report.proto
+++ b/components/metrics/proto/memory_leak_report.proto
@@ -61,6 +61,14 @@ message MemoryLeakReportProto {
   // Parameters used to initialize the leak detector.
   optional Params params = 3;
 
+  // The type of Chrome process on which this leak report was generated.
+  enum ProcessType {
+    UNKNOWN_PROCESS = 0;
+    BROWSER_PROCESS = 1;
+    RENDERER_PROCESS = 2;
+  }
+  optional ProcessType source_process = 5;
+
   //////////////////////////////////////////////////////////////////////////////
 
   // Represents a single snapshot of the internal bookkeeping of the Runtime