Adding blink gc memory dump infrastructure for thread specific dumps.

Source/platform/heap/BlinkGCMemoryDumpProvider.cpp

Index: Source/platform/heap/BlinkGCMemoryDumpProvider.cpp
diff --git a/Source/platform/heap/BlinkGCMemoryDumpProvider.cpp b/Source/platform/heap/BlinkGCMemoryDumpProvider.cpp
index 7db5047e1e7f5b82101318b4ab4bb99047ba2e7c..406ed90f8ba9e3d8aa98a4c018d2a6da571b81e9 100644
--- a/Source/platform/heap/BlinkGCMemoryDumpProvider.cpp
+++ b/Source/platform/heap/BlinkGCMemoryDumpProvider.cpp
@@ -6,6 +6,7 @@
 #include "Source/platform/heap/BlinkGCMemoryDumpProvider.h"
 
 #include "platform/heap/Handle.h"
+#include "public/platform/Platform.h"
 #include "public/platform/WebMemoryAllocatorDump.h"
 #include "public/platform/WebProcessMemoryDump.h"
 #include "wtf/StdLibExtras.h"
@@ -18,21 +19,46 @@ BlinkGCMemoryDumpProvider* BlinkGCMemoryDumpProvider::instance()
     return &instance;
 }
 
-bool BlinkGCMemoryDumpProvider::onMemoryDump(blink::WebProcessMemoryDump* memoryDump)
+BlinkGCMemoryDumpProvider::~BlinkGCMemoryDumpProvider()
+{
+}
+
+bool BlinkGCMemoryDumpProvider::onMemoryDump(WebProcessMemoryDump* memoryDump)
 {
+    // The current heap statistics are added to the memory dump.
     WebMemoryAllocatorDump* allocatorDump = memoryDump->createMemoryAllocatorDump("blink_gc");

[Primiano Tucci (use gerrit), 2015/05/22 19:45:57]

No need to do in this CL, but I think that, for the sake of consistency, in the
next CLs this should be moved to a public method in this class, and invoked by
ThreadState::PostGC, so we dump everything at the same time.

[ssid, 2015/05/26 11:08:43]

Done.

     allocatorDump->AddScalar("inner_size", "bytes", Heap::allocatedObjectSize());
     allocatorDump->AddScalar("outer_size", "bytes", Heap::allocatedSpace());
     allocatorDump->AddScalar("estimated_live_object_size", "bytes", Heap::estimatedLiveObjectSize());
+
+    // If available, the last GC memory statistics are added.
+    if (m_lastProcessMemoryDump.get())

[Primiano Tucci (use gerrit), 2015/05/22 19:45:57]

nit: OwnPtr, like scoped_ptr, has the implicit-conversion-to-bool operator, no
need of the .get() here

[ssid, 2015/05/26 11:08:42]

Done.

+        memoryDump->takeAllDumpsFrom(m_lastProcessMemoryDump.get());
+
+    // TODO(ssid): This should return false in the unlikely case that we didn't
+    // see a GC yet, which in turn will cause the dump to be invalidated. But,
+    // right now returning false will stop the manager from getting more dumps
+    // from this provider. So, always returns true while crbug.com/490783 gets
+    // fixed.
+
     return true;
 }
 
 BlinkGCMemoryDumpProvider::BlinkGCMemoryDumpProvider()

[Primiano Tucci (use gerrit), 2015/05/22 19:45:57]

micro-nit: I think it was right to keep this on the top, as it respect the decl
order (also people tend to expect ctors in the beginning)

[ssid, 2015/05/26 11:08:42]

Keeping it in decl order.

+    : m_lastProcessMemoryDump(adoptPtr(Platform::current()->createProcessMemoryDump()))
 {
 }
 
-BlinkGCMemoryDumpProvider::~BlinkGCMemoryDumpProvider()
+WebMemoryAllocatorDump* BlinkGCMemoryDumpProvider::createMemoryAllocatorDumpForLastGC(const String& absoluteName)
+{
+    return m_lastProcessMemoryDump->createMemoryAllocatorDump(absoluteName);
+}
+
+void BlinkGCMemoryDumpProvider::clearLastProcessMemoryDump()

[Primiano Tucci (use gerrit), 2015/05/22 19:45:57]

Nit: +GC (i.e. clearLastGC...)

[ssid, 2015/05/26 11:08:42]

Done.

 {
+    // TODO(ssid): Once the api for clearing dump is available, use that
+    // instead of this method here (crbug.com/491248).
+    m_lastProcessMemoryDump = adoptPtr(Platform::current()->createProcessMemoryDump());
 }
 
 } // namespace blink