[Tracing] Add hook to PartitionAlloc for heap profiling

third_party/WebKit/public/platform/WebMemoryDumpProvider.h

Index: third_party/WebKit/public/platform/WebMemoryDumpProvider.h
diff --git a/third_party/WebKit/public/platform/WebMemoryDumpProvider.h b/third_party/WebKit/public/platform/WebMemoryDumpProvider.h
index df151e8297bd2e1e5a406a6f8703a4d8a6bdff2a..62fbd13ee494538b8853cef798b4f09b3a765929 100644
--- a/third_party/WebKit/public/platform/WebMemoryDumpProvider.h
+++ b/third_party/WebKit/public/platform/WebMemoryDumpProvider.h
@@ -23,6 +23,11 @@ enum class WebMemoryDumpLevelOfDetail {
 // Platform::registerMemoryDumpProvider()) to dump stats for their allocators.
 class BLINK_PLATFORM_EXPORT WebMemoryDumpProvider {
 public:
+    // Function types for functions that can be called on alloc and free to do
+    // heap profiling.
+    typedef void AllocationHook(void* address, size_t);
+    typedef void FreeHook(void* address);
+
     virtual ~WebMemoryDumpProvider();
 
     // Called by the MemoryDumpManager when generating memory dumps.
@@ -32,6 +37,18 @@ public:
     // on success or false if anything went wrong and the dump should be
     // considered invalid.
     virtual bool onMemoryDump(WebMemoryDumpLevelOfDetail, WebProcessMemoryDump*) = 0;
+
+    // Because Blink cannot depend on base, heap profiling bookkeeping has to
+    // be done in the glue layer for now. This method allows the glue layer to
+    // detect whether the current dump provider supports heap profiling.
+    // TODO(ruuda): Remove once wtf can depend on base and do bookkeeping in the
+    // provider itself.
+    virtual bool supportsHeapProfiling() { return false; }
+
+    // Called by the memory dump manager to enable heap profiling (with
+    // non-null hook functions) or called to disable heap profiling (with null
+    // pointers).
+    virtual void onHeapProfilingEnabled(AllocationHook* allocationHook, FreeHook* freeHook) {}
 };
 
 } // namespace blink