[tracing] Introduce MemoryDumpArgs to enable light and heavy dumps

base/trace_event/memory_dump_provider.h

Index: base/trace_event/memory_dump_provider.h
diff --git a/base/trace_event/memory_dump_provider.h b/base/trace_event/memory_dump_provider.h
index 6e6551cc03988df685fb72d2e489e626ba583ab3..9fefdec5a4fd0a827017c3575b2567bd3538d612 100644
--- a/base/trace_event/memory_dump_provider.h
+++ b/base/trace_event/memory_dump_provider.h
@@ -13,15 +13,27 @@ namespace trace_event {
 
 class ProcessMemoryDump;
 
+// Contains information about the type of memory dump the MemoryDumpProvider
+// should generate on dump request. This is to control the size of dumps
+// generated.
+struct MemoryDumpArgs {
+  enum LevelOfDetail { LEVEL_OF_DETAIL_LOW, LEVEL_OF_DETAIL_HIGH };
+
+  LevelOfDetail level_of_detail;
+};
+
 // The contract interface that memory dump providers must implement.
 class BASE_EXPORT MemoryDumpProvider {
  public:
   // Called by the MemoryDumpManager when generating memory dumps.
-  // The embedder should return true if the |pmd| was successfully populated,
-  // false if something went wrong and the dump should be considered invalid.
+  // The |args| specify if the embedder should generate light/heavy dumps on
+  // dump requests. The embedder should return true if the |pmd| was
+  // successfully populated, false if something went wrong and the dump should
+  // be considered invalid.
   // (Note, the MemoryDumpManager has a fail-safe logic which will disable the
   // MemoryDumpProvider for the entire trace session if it fails consistently).
-  virtual bool OnMemoryDump(ProcessMemoryDump* pmd) = 0;
+  virtual bool OnMemoryDump(const MemoryDumpArgs& args,
+                            ProcessMemoryDump* pmd) = 0;
 
  protected:
   MemoryDumpProvider() {}