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..6d696b3f9652ece104349059c92a4e7f46e85062 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 +19,33 @@ BlinkGCMemoryDumpProvider* BlinkGCMemoryDumpProvider::instance()
     return &instance;
 }
 
+BlinkGCMemoryDumpProvider::~BlinkGCMemoryDumpProvider()
+{
+}
+
 bool BlinkGCMemoryDumpProvider::onMemoryDump(blink::WebProcessMemoryDump* memoryDump)
 {
+    m_currentProcessMemoryDump->clear();
+    Heap::collectGarbage(ThreadState::NoHeapPointersOnStack, ThreadState::TakeSnapshot, Heap::ForcedGC);

[Primiano Tucci (use gerrit), 2015/05/27 14:19:30]

Can you add a comment before this line clarifing that the collectGarbage will
create WMADs via createMemoryAllocatorDumpForCurrentGC in its call stack.

[ssid, 2015/05/27 14:39:33]

Added below.

+
     WebMemoryAllocatorDump* allocatorDump = memoryDump->createMemoryAllocatorDump("blink_gc");
     allocatorDump->AddScalar("inner_size", "bytes", Heap::allocatedObjectSize());
     allocatorDump->AddScalar("outer_size", "bytes", Heap::allocatedSpace());
     allocatorDump->AddScalar("estimated_live_object_size", "bytes", Heap::estimatedLiveObjectSize());
+
+    memoryDump->takeAllDumpsFrom(m_currentProcessMemoryDump.get());

[Primiano Tucci (use gerrit), 2015/05/27 14:19:30]

Or alternatively you can comment here saying:
merge all the dumps generated during the Heap::collectGarbage invocation

[ssid, 2015/05/27 14:39:33]

Done.

     return true;
 }
 
-BlinkGCMemoryDumpProvider::BlinkGCMemoryDumpProvider()
+WebMemoryAllocatorDump* BlinkGCMemoryDumpProvider::createMemoryAllocatorDumpForCurrentGC(const String& absoluteName)
 {
+    return m_currentProcessMemoryDump->createMemoryAllocatorDump(absoluteName);
 }
 
-BlinkGCMemoryDumpProvider::~BlinkGCMemoryDumpProvider()
+BlinkGCMemoryDumpProvider::BlinkGCMemoryDumpProvider()
 {
+    m_currentProcessMemoryDump = adoptPtr(Platform::current()->createProcessMemoryDump());

[Primiano Tucci (use gerrit), 2015/05/27 14:19:30]

Can you do this in the ctor initializer list? Otherwise I wonder if the clang
checked will falsely barf about m_currentProcessMemoryDump being not
initialized.

[ssid, 2015/05/27 14:39:33]

Done.

+    ASSERT(m_currentProcessMemoryDump);
 }
 
 } // namespace blink