metrics: Connect leak detector to allocator

components/metrics/leak_detector/leak_detector.h

Index: components/metrics/leak_detector/leak_detector.h
diff --git a/components/metrics/leak_detector/leak_detector.h b/components/metrics/leak_detector/leak_detector.h
index e23609444490d78765744910f02334b6f7fbbc8f..ea5df6528db46bcec488decddfb533f707d3f3c3 100644
--- a/components/metrics/leak_detector/leak_detector.h
+++ b/components/metrics/leak_detector/leak_detector.h
@@ -14,9 +14,11 @@
 #include "base/feature_list.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/threading/thread_checker.h"
+#include "components/metrics/leak_detector/leak_detector_impl.h"
 
 namespace metrics {
 
@@ -86,8 +88,29 @@ class LeakDetector {
   void RemoveObserver(Observer* observer);
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(LeakDetectorTest, AllocatorHooks);
   FRIEND_TEST_ALL_PREFIXES(LeakDetectorTest, NotifyObservers);
 
+  // Allocator hook function that processes each alloc. Performs sampling and
+  // unwinds call stack if necessary. Passes the allocated memory |ptr| and
+  // allocation size |size| along with call stack info to RecordAlloc().
+  static void AllocHook(const void* ptr, size_t size);
+
+  // Allocator hook function that processes each free. Performs sampling and
+  // passes the allocation address |ptr| to |impl_|.
+  static void FreeHook(const void* ptr);
+
+  // Give an pointer |ptr|, computes a hash of the pointer value and compares it
+  // against |sampling_factor_| to determine if it should be sampled. This
+  // allows the same pointer to be sampled during both alloc and free.
+  bool ShouldSample(const void* ptr) const;
+
+  // Given an allocation |ptr| with size |size|, and a call stack |call_stack|
+  // with depth of |depth| frames, passes it all to |impl_|. Then performs leak
+  // analysis if a sufficient interval of allocated bytes has passed since the
+  // previous analysis.
+  void RecordAlloc(const void* ptr, size_t size, int depth, void** call_stack);
+
   // Notifies all Observers in |observers_| with the given vector of leak
   // reports.
   void NotifyObservers(const std::vector<LeakReport>& reports);
@@ -95,9 +118,36 @@ class LeakDetector {
   // List of observers to notify when there's a leak report.
   base::ObserverList<Observer> observers_;
 
+  // Handles leak detection logic. Must be called under lock as LeakDetectorImpl
+  // uses shared resources.
+  scoped_ptr<leak_detector::LeakDetectorImpl> impl_;
+
   // For thread safety.
   base::ThreadChecker thread_checker_;
 
+  // Mapping size and address of Chrome binary in memory.
+  uintptr_t binary_mapping_addr_;
+  size_t binary_mapping_size_;
+
+  // Total number of bytes allocated, computed before sampling.
+  size_t total_alloc_size_;
+
+  // The value of |total_alloc_size_| the last time there was a leak analysis,
+  // rounded down to the nearest multiple of |analysis_interval_bytes_|.
+  size_t last_analysis_alloc_size_;
+
+  // Perform a leak analysis each time this many bytes have been allocated since
+  // the previous analysis.
+  size_t analysis_interval_bytes_;
+
+  // When unwinding call stacks, unwind no more than this number of frames.
+  size_t max_call_stack_unwind_depth_;
+
+  // Sampling factor used by ShouldSample(). It's full range of values
+  // corresponds to the allowable range of |sampling_rate| passed in during
+  // initialization: [0.0f, 1.0f] -> [0, UINT64_MAX].
+  uint64_t sampling_factor_;
+
   // For generating closures containing objects of this class.
   base::WeakPtrFactory<LeakDetector> weak_factory_;