diff -r 000000000000 -r 6474c204b198 toolkit/components/telemetry/ProcessedStack.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/components/telemetry/ProcessedStack.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,62 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ProcessedStack_h__
+#define ProcessedStack_h__
+
+#include <string>
+#include <vector>
+
+namespace mozilla {
+namespace Telemetry {
+
+// This class represents a stack trace and the modules referenced in that trace.
+// It is designed to be easy to read and write to disk or network and doesn't
+// include any logic on how to collect or read the information it stores.
+class ProcessedStack
+{
+public:
+  ProcessedStack();
+  size_t GetStackSize() const;
+  size_t GetNumModules() const;
+
+  struct Frame
+  {
+    // The offset of this program counter in its module or an absolute pc.
+    uintptr_t mOffset;
+    // The index to pass to GetModule to get the module this program counter
+    // was in.
+    uint16_t mModIndex;
+  };
+  struct Module
+  {
+    // The file name, /foo/bar/libxul.so for example.
+    std::string mName;
+    std::string mBreakpadId;
+
+    bool operator==(const Module& other) const;
+  };
+
+  const Frame &GetFrame(unsigned aIndex) const;
+  void AddFrame(const Frame& aFrame);
+  const Module &GetModule(unsigned aIndex) const;
+  void AddModule(const Module& aFrame);
+
+  void Clear();
+
+private:
+  std::vector<Module> mModules;
+  std::vector<Frame> mStack;
+};
+
+// Get the current list of loaded modules, filter and pair it to the provided
+// stack. We let the caller collect the stack since different callers have
+// different needs (current thread X main thread, stopping the thread, etc).
+ProcessedStack
+GetStackAndModules(const std::vector<uintptr_t> &aPCs);
+
+} // namespace Telemetry
+} // namespace mozilla
+#endif // ProcessedStack_h__