Add Web Resources usage to chrome://tracing.

third_party/WebKit/Source/core/fetch/Resource.cpp

Index: third_party/WebKit/Source/core/fetch/Resource.cpp
diff --git a/third_party/WebKit/Source/core/fetch/Resource.cpp b/third_party/WebKit/Source/core/fetch/Resource.cpp
index f1aaf35ded75c5e9d21ed0548344ec9bd3c24798..3a1ed1af141517ae6769dce6644826da3d3e6cd7 100644
--- a/third_party/WebKit/Source/core/fetch/Resource.cpp
+++ b/third_party/WebKit/Source/core/fetch/Resource.cpp
@@ -39,6 +39,7 @@
 #include "platform/TraceEvent.h"
 #include "platform/weborigin/KURL.h"
 #include "public/platform/Platform.h"
+#include "public/platform/WebProcessMemoryDump.h"
 #include "wtf/CurrentTime.h"
 #include "wtf/MathExtras.h"
 #include "wtf/StdLibExtras.h"
@@ -717,6 +718,36 @@ void Resource::prune()
     unlock();
 }
 
+void Resource::onMemoryDump(WebProcessMemoryDump* memoryDump) const
+{
+    const String dumpName = getMemoryDumpName();
+    WebMemoryAllocatorDump* dump = memoryDump->createMemoryAllocatorDump(dumpName);
+    dump->AddScalar("encoded_size", "bytes", m_encodedSize);
+    dump->AddScalar("decoded_size", "bytes", m_decodedSize);
+    if (!hasClients() && canDelete() && type() != MainResource) {

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

- !hasClients() isn't needed since canDelete() has the check.

- What is the type!=MainResource check for?

- I guess we can just check canDelete() here.

[ssid, 2015/09/29 11:06:36]

The pruneDeadResources prunes the resources with these checks.
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

So, I added the check for Main Resource. Removed it.

+        dump->AddScalar("dead_size", "bytes", m_encodedSize);
+    } else {
+        dump->AddScalar("live_size", "bytes", m_encodedSize);
+    }
+
+    size_t totalSize = encodedSize() + overheadSize();
+    dump->AddScalar("purged_size", "bytes", wasPurged() ? totalSize : 0);
+    if (m_data) {
+        dump->AddScalar("purgeable_size", "bytes", isPurgeable() ? 0 : totalSize);

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

It won't make sense to dump both purged_size and purgeable_size. Maybe can we
just dump isPurgeable()?

BTW, when wasPurged() returns true, does it mean that encodedSize() returns 0?

[ssid, 2015/09/29 11:06:37]

If was_purged returns true, it meand that discardable memory was evicted from
the system. This would mean that the discardable manager accounts 0 for it, and
I am not taking the encoded)size as the main size for the dump, I am considering
the size returned by discardable manager internally as the size of the buffer.
So, yes I can remove the purged_size.

+        m_data->onMemoryDump(dumpName, memoryDump);
+    }
+
+    const String overheadName = dumpName + "/overhead";
+    WebMemoryAllocatorDump* overheadDump = memoryDump->createMemoryAllocatorDump(overheadName);
+    overheadDump->AddScalar("size", "bytes", overheadSize());
+    memoryDump->AddSuballocation(overheadDump->guid(), String(WTF::Partitions::allocatorPoolNameForTracing()));
+}
+
+String Resource::getMemoryDumpName() const
+{
+    return String::format("web_cache/%s_resources/%ld", resourceTypeToString(type(), options().initiatorInfo), m_identifier);
+}
+
 void Resource::setResourceToRevalidate(Resource* resource)
 {
     ASSERT(resource);