Implement GetSkiaTraceMemoryDump and AddSuballocation on chrome blink platform impl

content/child/web_process_memory_dump_impl.cc

Index: content/child/web_process_memory_dump_impl.cc
diff --git a/content/child/web_process_memory_dump_impl.cc b/content/child/web_process_memory_dump_impl.cc
index 688b6c1616690ad85a52505759f6414de37044af..4f53cb469f911b03ed4324dbe9bcaebc9eccdd91 100644
--- a/content/child/web_process_memory_dump_impl.cc
+++ b/content/child/web_process_memory_dump_impl.cc
@@ -6,6 +6,7 @@
 
 #include "base/trace_event/process_memory_dump.h"
 #include "content/child/web_memory_allocator_dump_impl.h"
+#include "skia/ext/SkTraceMemoryDump_chrome.h"
 
 namespace content {
 
@@ -132,4 +133,20 @@ void WebProcessMemoryDumpImpl::AddOwnershipEdge(
       base::trace_event::MemoryAllocatorDumpGuid(target));
 }
 
+void WebProcessMemoryDumpImpl::AddSuballocation(
+    blink::WebMemoryAllocatorDumpGuid source,
+    const blink::WebString& targetNodeName) {
+  process_memory_dump_->AddSuballocation(
+      base::trace_event::MemoryAllocatorDumpGuid(source),
+      targetNodeName.utf8());
+}
+
+SkTraceMemoryDump* WebProcessMemoryDumpImpl::CreateDumpAdapterForSkia(
+    blink::WebMemoryDumpLevelOfDetail levelOfDetail,

[Primiano Tucci (use gerrit), 2015/09/09 17:21:36]

Wait I realized only now: you don't seem to make any use of levelOfDetail. Why
is this an rgument at all? Don't you knoe the level of detail int he current
WPMDImpl?

Let's have a quick chat on this, I think you can remove this argument both from
here and the other (blink) CL.

[ssid, 2015/09/10 11:08:26]

I have uploaded the Cl in skia impl to add one more arg. So, I have added it
here since I don't have to change the blink code. I could just add it to this
class instead, so adding it here. Updated the skia construct as well.

+    const blink::WebString& dumpNamePrefix) {
+  sk_trace_dump_list_.push_back(new skia::SkTraceMemoryDump_Chrome(
+      dumpNamePrefix.utf8().data(), process_memory_dump_));

[Primiano Tucci (use gerrit), 2015/09/09 16:16:41]

I realized this just now, but would have been a bit clearer if 
SkTraceMemoryDump_Chrome took a std::string& (that ctor is internal to chrome
and not exposed to skia, right?)
By looking at the header it is not clear whether the char* string is deep-copied
or you take the ptr.
If it was the latter this would have been wrong. But I checked the code and you
actually copy there the char* into a std::String.

If you get a change to re-iterate on that file, you should probably make the
prefix argument a std::string& (unless there is something here I'm not thingking
about).

This LGTM anyways.

[ssid, 2015/09/10 11:08:26]

hm, okay. Will fix this in next CL. Thanks

+  return sk_trace_dump_list_.back();
+}
+
 }  // namespace content