Adding dump provider for dumping java heap sizes on android.

base/trace_event/java_heap_dump_provider_android.cc

Index: base/trace_event/java_heap_dump_provider_android.cc
diff --git a/base/trace_event/java_heap_dump_provider_android.cc b/base/trace_event/java_heap_dump_provider_android.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3517f76b8039cfa21b0eabbaae3ce34a8eb7758f
--- /dev/null
+++ b/base/trace_event/java_heap_dump_provider_android.cc
@@ -0,0 +1,54 @@
+// Copyright 2015 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.
+
+#include "base/trace_event/java_heap_dump_provider_android.h"
+
+#include "base/android/java_runtime.h"
+#include "base/trace_event/process_memory_dump.h"
+
+namespace base {
+namespace trace_event {
+
+namespace {
+
+const char kDumperFriendlyName[] = "AndroidJavaHeap";

[Primiano Tucci (use gerrit), 2015/04/21 18:36:01]

just "Java Heap"

[ssid, 2015/04/22 10:40:11]

Done.

+const char kDumperName[] = "android_java_heap";

[Primiano Tucci (use gerrit), 2015/04/21 18:36:01]

"java_heap"

[ssid, 2015/04/22 10:40:11]

Done.

+
+}  // namespace
+
+// static
+AndrdoiJavaHeapDumpProvider* AndrdoiJavaHeapDumpProvider::GetInstance() {

[Primiano Tucci (use gerrit), 2015/04/21 18:36:01]

Just call it JavaHeapDumpProvider, remove android (but keep it in the file name
to get the auto filtering)

[ssid, 2015/04/22 10:40:11]

Done.

+  return Singleton<AndrdoiJavaHeapDumpProvider,
+                   LeakySingletonTraits<AndrdoiJavaHeapDumpProvider>>::get();
+}
+
+AndrdoiJavaHeapDumpProvider::AndrdoiJavaHeapDumpProvider() {
+}
+
+AndrdoiJavaHeapDumpProvider::~AndrdoiJavaHeapDumpProvider() {
+}
+
+// Called at trace dump point time. Creates a snapshot with the memory counters
+// for the current process.
+bool AndrdoiJavaHeapDumpProvider::DumpInto(ProcessMemoryDump* pmd) {
+  MemoryAllocatorDump* dump =
+      pmd->CreateAllocatorDump(kDumperName, MemoryAllocatorDump::kRootHeap);
+
+  // The total size used by java heap and available memory out of the total that

[Primiano Tucci (use gerrit), 2015/04/21 18:36:01]

I'd probably just say:
"These numbers come from java.lang.Runtime() stats"

[ssid, 2015/04/22 10:40:11]

Done.

+  // can be allocated for objects are obtained from java.lang.Runtime object.
+  long total_heap_memory, free_heap_memory;

[Primiano Tucci (use gerrit), 2015/04/21 18:36:01]

remove "memory", as should be pretty clear.
just total_heap_size and free_heap_size

[Primiano Tucci (use gerrit), 2015/04/21 18:36:01]

Initialize them to zero.
Also I think that our code style doesn't allow multiple decl in the same line,
just have two distinct lines.

[ssid, 2015/04/22 10:40:11]

Done.

+  android::JavaRuntime::GetMemoryUsage(&total_heap_memory, &free_heap_memory);
+  dump->set_physical_size_in_bytes(total_heap_memory);
+  dump->set_allocated_objects_count(0);
+  dump->set_allocated_objects_size_in_bytes(total_heap_memory -
+                                            free_heap_memory);
+  return true;
+}
+
+const char* AndrdoiJavaHeapDumpProvider::GetFriendlyName() const {
+  return kDumperFriendlyName;
+}
+
+}  // namespace trace_event
+}  // namespace base