Adding blink gc memory dump infrastructure for thread specific dumps.

Source/platform/heap/Heap.cpp

Index: Source/platform/heap/Heap.cpp
diff --git a/Source/platform/heap/Heap.cpp b/Source/platform/heap/Heap.cpp
index c938b3a3ffe05e998fc64b37b3048150329650cc..5727f925ad7393ed6ef082b479c0680cce4f4cc8 100644
--- a/Source/platform/heap/Heap.cpp
+++ b/Source/platform/heap/Heap.cpp
@@ -41,6 +41,8 @@
 #include "platform/heap/SafePoint.h"
 #include "platform/heap/ThreadState.h"
 #include "public/platform/Platform.h"
+#include "public/platform/WebMemoryAllocatorDump.h"
+#include "public/platform/WebProcessMemoryDump.h"
 #include "wtf/Assertions.h"
 #include "wtf/ContainerAnnotations.h"
 #include "wtf/LeakAnnotations.h"
@@ -213,6 +215,20 @@ void BaseHeap::cleanupPages()
     m_firstPage = nullptr;
 }
 
+void BaseHeap::dumpMemoryInto(WebProcessMemoryDump* memoryDump, const String* allocatorBaseName)

[Primiano Tucci (use gerrit), 2015/05/21 18:43:10]

maybe s/allocatorBaseName/dumpBaseName/... or just dumpName, unless you plan to
extend it in the future (I guess that is the case)
ah and const* -> const&

[ssid, 2015/05/22 13:34:06]

Done.

+{
+    // Returns if there is no page used in the heap.
+    if (!m_firstPage)
+        return;

[Primiano Tucci (use gerrit), 2015/05/21 18:43:10]

Hmm I'd much rather prefer that you dump a zero in this case (or you might cause
headaches to Peter's UI)
Which looks like, just remove these two lines and the for () loop will take care
as it is

[ssid, 2015/05/22 13:34:06]

Done.

+
+    size_t pageCount = 0;
+    for (BasePage* page = m_firstPage; page; page = page->next()) {
+        pageCount++;
+    }
+    WebMemoryAllocatorDump* allocatorDump = memoryDump->createMemoryAllocatorDump(*allocatorBaseName);
+    allocatorDump->AddScalar("blink_page_count", "objects", pageCount);
+}
+
 #if ENABLE(ASSERT) || ENABLE(GC_PROFILING)
 BasePage* BaseHeap::findPageFromAddress(Address address)
 {