Add Web Resources usage to chrome://tracing.

third_party/WebKit/Source/platform/SharedBuffer.cpp

Index: third_party/WebKit/Source/platform/SharedBuffer.cpp
diff --git a/third_party/WebKit/Source/platform/SharedBuffer.cpp b/third_party/WebKit/Source/platform/SharedBuffer.cpp
index d678a28fa5fb01dac6864ab458504c56fbf71b20..3c5b2996a55529d5604115cafa21eefd9c660fc4 100644
--- a/third_party/WebKit/Source/platform/SharedBuffer.cpp
+++ b/third_party/WebKit/Source/platform/SharedBuffer.cpp
@@ -27,6 +27,7 @@
 #include "config.h"
 #include "platform/SharedBuffer.h"
 
+#include "public/platform/WebProcessMemoryDump.h"
 #include "wtf/text/UTF8.h"
 #include "wtf/text/Unicode.h"
 
@@ -410,4 +411,18 @@ bool SharedBuffer::isLocked() const
     return m_buffer.isLocked();
 }
 
+void SharedBuffer::onMemoryDump(const String& dumpPrefix, WebProcessMemoryDump* memoryDump) const
+{
+    m_buffer.onMemoryDump(dumpPrefix + "/buffer", memoryDump);

[haraken, 2015/09/28 14:54:02]

/buffer => /shared_buffer

[ssid, 2015/09/28 16:24:39]

Done.

+
+    if (m_size - m_buffer.size() > 0) {

[haraken, 2015/09/28 14:54:02]

Wouldn't it be enough to check:

  if (!m_buffer.size()) {  // This means that data is in segments.
    ...;
  }

?

[ssid, 2015/09/28 16:24:39]

I was wondering that both can be used at the same time and data is moved in
parts. Changed it now.

[haraken, 2015/09/29 02:44:48]

Shall we add an ASSERT about it?

+        // If there is data in the segments, then it should have been allocated
+        // using fastMalloc.
+        const String dataDumpName = dumpPrefix + "/data";

[haraken, 2015/09/28 14:54:02]

/data => /segments

[ssid, 2015/09/28 16:24:38]

Done.

+        auto dump = memoryDump->createMemoryAllocatorDump(dataDumpName);
+        dump->AddScalar("size", "bytes", m_size - m_buffer.size());

[haraken, 2015/09/28 14:54:02]

At this point, I think m_buffer.size() is guaranteed to be 0. So this can be
just m_size.

[ssid, 2015/09/28 16:24:39]

Yeah I was just paranoid..

+        memoryDump->AddSuballocation(dump->guid(), "malloc/allocated_objects");
+    }
+}
+
 } // namespace blink