[tracing] Introduce MemoryDumpArgs to enable light and heavy dumps

base/trace_event/memory_allocator_dump_unittest.cc

Index: base/trace_event/memory_allocator_dump_unittest.cc
diff --git a/base/trace_event/memory_allocator_dump_unittest.cc b/base/trace_event/memory_allocator_dump_unittest.cc
index 85b98d65511ed556bbdb27679c65038c497a5266..0c9309cabc68903c639ab33f9fb6f5ac4db0ffbf 100644
--- a/base/trace_event/memory_allocator_dump_unittest.cc
+++ b/base/trace_event/memory_allocator_dump_unittest.cc
@@ -21,7 +21,8 @@ namespace {
 
 class FakeMemoryAllocatorDumpProvider : public MemoryDumpProvider {
  public:
-  bool OnMemoryDump(ProcessMemoryDump* pmd) override {
+  bool OnMemoryDump(const MemoryDumpArgs& args,
+                    ProcessMemoryDump* pmd) override {
     MemoryAllocatorDump* root_heap =
         pmd->CreateAllocatorDump("foobar_allocator");
 
@@ -126,7 +127,8 @@ TEST(MemoryAllocatorDumpTest, DumpIntoProcessMemoryDump) {
   FakeMemoryAllocatorDumpProvider fmadp;
   ProcessMemoryDump pmd(make_scoped_refptr(new MemoryDumpSessionState()));
 
-  fmadp.OnMemoryDump(&pmd);
+  fmadp.OnMemoryDump(MemoryDumpArgs(MemoryDumpArgs::LEVEL_OF_DETAIL_HIGH),
+                     &pmd);
 
   ASSERT_EQ(3u, pmd.allocator_dumps().size());