updates to FrameStatsObserver API

- Rename to FrameMetrics to avoid collision with existing
  android.view.FrameStats class
- Make FrameMetricsObserver implementation detail,
  exposing FrameMetricsListener interface as public API
  and wrapping in FrameStatsObserver to maintain state
- Remove dropped frame count call, in favor of passing as
  parameter to callback method.
- Move away from raw timestamp access in favor of Metric IDs
  which represent higher-level, more stable stages in a frame
  lifecycle and match the categories exposed in the onscreen
  bars.
- Support many-to-many Window<->FrameMetricsListener relationship

Change-Id: I00e741d664d4c868b1b6d0131a23f8316bd8c5c2
diff --git a/libs/hwui/FrameStatsObserver.h b/libs/hwui/FrameMetricsObserver.h
similarity index 86%
rename from libs/hwui/FrameStatsObserver.h
rename to libs/hwui/FrameMetricsObserver.h
index 7abc9f1..2b42a80 100644
--- a/libs/hwui/FrameStatsObserver.h
+++ b/libs/hwui/FrameMetricsObserver.h
@@ -23,9 +23,9 @@
 namespace android {
 namespace uirenderer {
 
-class FrameStatsObserver : public VirtualLightRefBase {
+class FrameMetricsObserver : public VirtualLightRefBase {
 public:
-    virtual void notify(BufferPool::Buffer* buffer);
+    virtual void notify(BufferPool::Buffer* buffer, int dropCount);
 };
 
 }; // namespace uirenderer
diff --git a/libs/hwui/FrameStatsReporter.h b/libs/hwui/FrameMetricsReporter.h
similarity index 83%
rename from libs/hwui/FrameStatsReporter.h
rename to libs/hwui/FrameMetricsReporter.h
index b8a9432..0831d24 100644
--- a/libs/hwui/FrameStatsReporter.h
+++ b/libs/hwui/FrameMetricsReporter.h
@@ -21,7 +21,7 @@
 
 #include "BufferPool.h"
 #include "FrameInfo.h"
-#include "FrameStatsObserver.h"
+#include "FrameMetricsObserver.h"
 
 #include <string.h>
 #include <vector>
@@ -29,18 +29,18 @@
 namespace android {
 namespace uirenderer {
 
-class FrameStatsReporter {
+class FrameMetricsReporter {
 public:
-    FrameStatsReporter() {
+    FrameMetricsReporter() {
         mBufferPool = new BufferPool(kBufferSize, kBufferCount);
         LOG_ALWAYS_FATAL_IF(mBufferPool.get() == nullptr, "OOM: unable to allocate buffer pool");
     }
 
-    void addObserver(FrameStatsObserver* observer) {
+    void addObserver(FrameMetricsObserver* observer) {
         mObservers.push_back(observer);
     }
 
-    bool removeObserver(FrameStatsObserver* observer) {
+    bool removeObserver(FrameMetricsObserver* observer) {
         for (size_t i = 0; i < mObservers.size(); i++) {
             if (mObservers[i].get() == observer) {
                 mObservers.erase(mObservers.begin() + i);
@@ -54,7 +54,7 @@
         return mObservers.size() > 0;
     }
 
-    void reportFrameStats(const int64_t* stats) {
+    void reportFrameMetrics(const int64_t* stats) {
         BufferPool::Buffer* statsBuffer = mBufferPool->acquire();
 
         if (statsBuffer != nullptr) {
@@ -63,11 +63,12 @@
 
             // notify on requested threads
             for (size_t i = 0; i < mObservers.size(); i++) {
-                mObservers[i]->notify(statsBuffer);
+                mObservers[i]->notify(statsBuffer, mDroppedReports);
             }
 
             // drop our reference
             statsBuffer->release();
+            mDroppedReports = 0;
         } else {
             mDroppedReports++;
         }
@@ -79,7 +80,7 @@
     static const size_t kBufferCount = 3;
     static const size_t kBufferSize = static_cast<size_t>(FrameInfoIndex::NumIndexes);
 
-    std::vector< sp<FrameStatsObserver> > mObservers;
+    std::vector< sp<FrameMetricsObserver> > mObservers;
 
     sp<BufferPool> mBufferPool;
 
diff --git a/libs/hwui/renderthread/CanvasContext.cpp b/libs/hwui/renderthread/CanvasContext.cpp
index ea702c0..4f528b1 100644
--- a/libs/hwui/renderthread/CanvasContext.cpp
+++ b/libs/hwui/renderthread/CanvasContext.cpp
@@ -507,8 +507,8 @@
 
     mJankTracker.addFrame(*mCurrentFrameInfo);
     mRenderThread.jankTracker().addFrame(*mCurrentFrameInfo);
-    if (CC_UNLIKELY(mFrameStatsReporter.get() != nullptr)) {
-        mFrameStatsReporter->reportFrameStats(mCurrentFrameInfo->data());
+    if (CC_UNLIKELY(mFrameMetricsReporter.get() != nullptr)) {
+        mFrameMetricsReporter->reportFrameMetrics(mCurrentFrameInfo->data());
     }
 
     GpuMemoryTracker::onFrameCompleted();
diff --git a/libs/hwui/renderthread/CanvasContext.h b/libs/hwui/renderthread/CanvasContext.h
index 168166e..1f81970 100644
--- a/libs/hwui/renderthread/CanvasContext.h
+++ b/libs/hwui/renderthread/CanvasContext.h
@@ -20,7 +20,7 @@
 #include "DamageAccumulator.h"
 #include "FrameInfo.h"
 #include "FrameInfoVisualizer.h"
-#include "FrameStatsReporter.h"
+#include "FrameMetricsReporter.h"
 #include "IContextFactory.h"
 #include "LayerUpdateQueue.h"
 #include "RenderNode.h"
@@ -142,26 +142,26 @@
         return mRenderThread.renderState();
     }
 
-    void addFrameStatsObserver(FrameStatsObserver* observer) {
-        if (mFrameStatsReporter.get() == nullptr) {
-            mFrameStatsReporter.reset(new FrameStatsReporter());
+    void addFrameMetricsObserver(FrameMetricsObserver* observer) {
+        if (mFrameMetricsReporter.get() == nullptr) {
+            mFrameMetricsReporter.reset(new FrameMetricsReporter());
         }
 
-        mFrameStatsReporter->addObserver(observer);
+        mFrameMetricsReporter->addObserver(observer);
     }
 
-    void removeFrameStatsObserver(FrameStatsObserver* observer) {
-        if (mFrameStatsReporter.get() != nullptr) {
-            mFrameStatsReporter->removeObserver(observer);
-            if (!mFrameStatsReporter->hasObservers()) {
-                mFrameStatsReporter.reset(nullptr);
+    void removeFrameMetricsObserver(FrameMetricsObserver* observer) {
+        if (mFrameMetricsReporter.get() != nullptr) {
+            mFrameMetricsReporter->removeObserver(observer);
+            if (!mFrameMetricsReporter->hasObservers()) {
+                mFrameMetricsReporter.reset(nullptr);
             }
         }
     }
 
     long getDroppedFrameReportCount() {
-        if (mFrameStatsReporter.get() != nullptr) {
-            return mFrameStatsReporter->getDroppedReports();
+        if (mFrameMetricsReporter.get() != nullptr) {
+            return mFrameMetricsReporter->getDroppedReports();
         }
 
         return 0;
@@ -215,7 +215,7 @@
     std::string mName;
     JankTracker mJankTracker;
     FrameInfoVisualizer mProfiler;
-    std::unique_ptr<FrameStatsReporter> mFrameStatsReporter;
+    std::unique_ptr<FrameMetricsReporter> mFrameMetricsReporter;
 
     std::set<RenderNode*> mPrefetechedLayers;
 
diff --git a/libs/hwui/renderthread/RenderProxy.cpp b/libs/hwui/renderthread/RenderProxy.cpp
index 7c6cd7e..04223a7 100644
--- a/libs/hwui/renderthread/RenderProxy.cpp
+++ b/libs/hwui/renderthread/RenderProxy.cpp
@@ -568,17 +568,17 @@
     post(task);
 }
 
-CREATE_BRIDGE2(addFrameStatsObserver, CanvasContext* context,
-        FrameStatsObserver* frameStatsObserver) {
-   args->context->addFrameStatsObserver(args->frameStatsObserver);
+CREATE_BRIDGE2(addFrameMetricsObserver, CanvasContext* context,
+        FrameMetricsObserver* frameStatsObserver) {
+   args->context->addFrameMetricsObserver(args->frameStatsObserver);
    if (args->frameStatsObserver != nullptr) {
        args->frameStatsObserver->decStrong(args->context);
    }
    return nullptr;
 }
 
-void RenderProxy::addFrameStatsObserver(FrameStatsObserver* observer) {
-    SETUP_TASK(addFrameStatsObserver);
+void RenderProxy::addFrameMetricsObserver(FrameMetricsObserver* observer) {
+    SETUP_TASK(addFrameMetricsObserver);
     args->context = mContext;
     args->frameStatsObserver = observer;
     if (observer != nullptr) {
@@ -587,17 +587,17 @@
     post(task);
 }
 
-CREATE_BRIDGE2(removeFrameStatsObserver, CanvasContext* context,
-        FrameStatsObserver* frameStatsObserver) {
-   args->context->removeFrameStatsObserver(args->frameStatsObserver);
+CREATE_BRIDGE2(removeFrameMetricsObserver, CanvasContext* context,
+        FrameMetricsObserver* frameStatsObserver) {
+   args->context->removeFrameMetricsObserver(args->frameStatsObserver);
    if (args->frameStatsObserver != nullptr) {
        args->frameStatsObserver->decStrong(args->context);
    }
    return nullptr;
 }
 
-void RenderProxy::removeFrameStatsObserver(FrameStatsObserver* observer) {
-    SETUP_TASK(removeFrameStatsObserver);
+void RenderProxy::removeFrameMetricsObserver(FrameMetricsObserver* observer) {
+    SETUP_TASK(removeFrameMetricsObserver);
     args->context = mContext;
     args->frameStatsObserver = observer;
     if (observer != nullptr) {
@@ -606,16 +606,6 @@
     post(task);
 }
 
-CREATE_BRIDGE1(getDroppedFrameReportCount, CanvasContext* context) {
-    return (void*) args->context->getDroppedFrameReportCount();
-}
-
-long RenderProxy::getDroppedFrameReportCount() {
-    SETUP_TASK(getDroppedFrameReportCount);
-    args->context = mContext;
-    return (long) postAndWait(task);
-}
-
 void RenderProxy::post(RenderTask* task) {
     mRenderThread.queue(task);
 }
diff --git a/libs/hwui/renderthread/RenderProxy.h b/libs/hwui/renderthread/RenderProxy.h
index 178724a..8d65a82 100644
--- a/libs/hwui/renderthread/RenderProxy.h
+++ b/libs/hwui/renderthread/RenderProxy.h
@@ -29,7 +29,7 @@
 #include <utils/StrongPointer.h>
 
 #include "../Caches.h"
-#include "../FrameStatsObserver.h"
+#include "../FrameMetricsObserver.h"
 #include "../IContextFactory.h"
 #include "CanvasContext.h"
 #include "DrawFrameTask.h"
@@ -113,8 +113,8 @@
     ANDROID_API void drawRenderNode(RenderNode* node);
     ANDROID_API void setContentDrawBounds(int left, int top, int right, int bottom);
 
-    ANDROID_API void addFrameStatsObserver(FrameStatsObserver* observer);
-    ANDROID_API void removeFrameStatsObserver(FrameStatsObserver* observer);
+    ANDROID_API void addFrameMetricsObserver(FrameMetricsObserver* observer);
+    ANDROID_API void removeFrameMetricsObserver(FrameMetricsObserver* observer);
     ANDROID_API long getDroppedFrameReportCount();
 
 private: