Use LatencyInfoSwapPromise to track LatencyInfo through compositor

cc/base/swap_promise.h

Index: cc/base/swap_promise.h
diff --git a/cc/base/swap_promise.h b/cc/base/swap_promise.h
index 90bf6af53a6a0909484cd897b1ccab6a2cbe3844..7328f12935252424d44bd95e7ff5f63ee1eb8297 100644
--- a/cc/base/swap_promise.h
+++ b/cc/base/swap_promise.h
@@ -5,6 +5,9 @@
 #ifndef CC_BASE_SWAP_PROMISE_H_
 #define CC_BASE_SWAP_PROMISE_H_
 
+#include "base/compiler_specific.h"
+#include "ui/events/latency_info.h"
+
 namespace cc {
 
 const unsigned int kMaxQueuedSwapPromiseNumber = 100;
@@ -29,8 +32,10 @@ const unsigned int kMaxQueuedSwapPromiseNumber = 100;
 // DidSwap() and DidNotSwap().
 class SwapPromise {
  public:
-  SwapPromise() {}
-  virtual ~SwapPromise() {}
+  enum SwapPromiseType {
+    SWAP_PROMISE_UNKNOWN,
+    SWAP_PROMISE_LATENCY_INFO,
+  };
 
   enum DidNotSwapReason {
     DID_NOT_SWAP_UNKNOWN,
@@ -39,8 +44,30 @@ class SwapPromise {
     SWAP_PROMISE_LIST_OVERFLOW,
   };
 
+  explicit SwapPromise(SwapPromiseType type);
+  virtual ~SwapPromise();
+
+  SwapPromiseType type();
+
   virtual void DidSwap() = 0;
   virtual void DidNotSwap(DidNotSwapReason reason) = 0;
+
+ protected:
+  SwapPromiseType type_;
+};
+
+class LatencyInfoSwapPromise : public SwapPromise {

[danakj, 2013/11/26 19:17:53]

one class per file please

[Yufeng Shen (Slow to review), 2013/11/27 20:05:33]

Done.

+ public:
+  explicit LatencyInfoSwapPromise(const ui::LatencyInfo& latency_info);
+  virtual ~LatencyInfoSwapPromise();
+
+  virtual void DidSwap() OVERRIDE;
+  virtual void DidNotSwap(DidNotSwapReason reason) OVERRIDE;
+
+  const ui::LatencyInfo& GetLatencyInfo();
+
+ private:
+  ui::LatencyInfo latency_;
 };
 
 }  // namespace cc