Expose api to dump discardable memory usage in blink.

This CL adds an api to WebProcessMemoryDump for using
base::DiscardableMemory::CreateMemoryAllocatorDump from blink, which is
used to dump discardable memory objects, taking into account if the
memory is purged or not.

BUG=520842

Review URL: https://codereview.chromium.org/1372573003

Cr-Commit-Position: refs/heads/master@{#353262}

4 files changed, 29 insertions, 0 deletions

diff --git a/content/child/web_discardable_memory_impl.cc b/content/child/web_discardable_memory_impl.cc
index e2ea7a2..18042b2 100644
--- a/content/child/web_discardable_memory_impl.cc
+++ b/content/child/web_discardable_memory_impl.cc
@@ -6,6 +6,8 @@
 
 #include "base/memory/discardable_memory.h"
 #include "base/memory/discardable_memory_allocator.h"
+#include "content/child/web_process_memory_dump_impl.h"
+#include "third_party/WebKit/public/platform/WebString.h"
 
 namespace content {
 
@@ -31,6 +33,14 @@ void* WebDiscardableMemoryImpl::data() {
   return discardable_->data();
 }
 
+blink::WebMemoryAllocatorDump*
+WebDiscardableMemoryImpl::createMemoryAllocatorDump(
+    const blink::WebString& name,
+    blink::WebProcessMemoryDump* wpmd) const {
+  return static_cast<content::WebProcessMemoryDumpImpl*>(wpmd)
+      ->CreateDiscardableMemoryAllocatorDump(name.utf8(), discardable_.get());
+}
+
 WebDiscardableMemoryImpl::WebDiscardableMemoryImpl(
     scoped_ptr<base::DiscardableMemory> memory)
     : discardable_(memory.Pass()) {
diff --git a/content/child/web_discardable_memory_impl.h b/content/child/web_discardable_memory_impl.h
index c3c8f5d..4c589a4 100644
--- a/content/child/web_discardable_memory_impl.h
+++ b/content/child/web_discardable_memory_impl.h
@@ -27,6 +27,9 @@ class WebDiscardableMemoryImpl : public blink::WebDiscardableMemory {
   bool lock() override;
   void unlock() override;
   void* data() override;
+  blink::WebMemoryAllocatorDump* createMemoryAllocatorDump(
+      const blink::WebString& name,
+      blink::WebProcessMemoryDump* wpmd) const override;
 
  private:
   WebDiscardableMemoryImpl(scoped_ptr<base::DiscardableMemory> memory);
diff --git a/content/child/web_process_memory_dump_impl.cc b/content/child/web_process_memory_dump_impl.cc
index 95197da..1d769dd 100644
--- a/content/child/web_process_memory_dump_impl.cc
+++ b/content/child/web_process_memory_dump_impl.cc
@@ -4,6 +4,7 @@
 
 #include "content/child/web_process_memory_dump_impl.h"
 
+#include "base/memory/discardable_memory.h"
 #include "base/trace_event/process_memory_dump.h"
 #include "content/child/web_memory_allocator_dump_impl.h"
 #include "skia/ext/skia_trace_memory_dump_impl.h"
@@ -149,4 +150,14 @@ SkTraceMemoryDump* WebProcessMemoryDumpImpl::CreateDumpAdapterForSkia(
   return sk_trace_dump_list_.back();
 }
 
+blink::WebMemoryAllocatorDump*
+WebProcessMemoryDumpImpl::CreateDiscardableMemoryAllocatorDump(
+    const std::string& name,
+    base::DiscardableMemory* discardable) {
+  base::trace_event::MemoryAllocatorDump* dump =
+      discardable->CreateMemoryAllocatorDump(name.c_str(),
+                                             process_memory_dump_);
+  return createWebMemoryAllocatorDump(dump);
+}
+
 }  // namespace content
diff --git a/content/child/web_process_memory_dump_impl.h b/content/child/web_process_memory_dump_impl.h
index 33f2fd2..4e5fb26 100644
--- a/content/child/web_process_memory_dump_impl.h
+++ b/content/child/web_process_memory_dump_impl.h
@@ -14,6 +14,7 @@
 #include "third_party/WebKit/public/platform/WebProcessMemoryDump.h"
 
 namespace base {
+class DiscardableMemory;
 namespace trace_event {
 class MemoryAllocatorDump;
 class ProcessMemoryDump;
@@ -69,6 +70,10 @@ class CONTENT_EXPORT WebProcessMemoryDumpImpl final
     return process_memory_dump_;
   }
 
+  blink::WebMemoryAllocatorDump* CreateDiscardableMemoryAllocatorDump(
+      const std::string& name,
+      base::DiscardableMemory* discardable);
+
  private:
   FRIEND_TEST_ALL_PREFIXES(WebProcessMemoryDumpImplTest, IntegrationTest);