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..ed35f1ac65c61c2330b8407d3590c76b3b57491d 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"

[ssid, 2015/09/04 08:54:00]

Also, deps addition is not required, it is already added in parent directory
DEPS :)

 
 namespace content {
 
@@ -132,4 +133,11 @@ void WebProcessMemoryDumpImpl::AddOwnershipEdge(
       base::trace_event::MemoryAllocatorDumpGuid(target));
 }
 
+SkTraceMemoryDump* WebProcessMemoryDumpImpl::CreateSkiaTraceMemoryDump(
+    const blink::WebString& dumpNamePrefix) {
+  sk_trace_dump_.reset(new skia::SkTraceMemoryDump_Chrome(

[Primiano Tucci (use gerrit), 2015/09/04 10:02:16]

Hmm if you store it into a scoped_ptr implies that you can create only one
adapter (with one prefix) at all for each dump. Isn't this a bit limiting? 
I think the options here are:
 A. You keep the memory ownership of the skia wrappers here, but make
sk_trace_Dump a ScopedVector instead.

 B. You move the memory ownership of this to the caller (so return a naked
pointer) and the caller has the responsibility of owning and destroying properly
the wrapper.

I'd go for A as, IIRC, the skia wrapper cannot outlive the process memory dump.
BUt please document that in the comment of Create... method.

[ssid, 2015/09/07 17:29:53]

Done.

+      dumpNamePrefix.utf8().data(), process_memory_dump_));
+  return sk_trace_dump_.get();
+}
+
 }  // namespace content