Ganesh: images upload to GPU performance fix (skip copying encoded data)

third_party/WebKit/Source/platform/graphics/ThreadSafeDataTransport.cpp

Index: third_party/WebKit/Source/platform/graphics/ThreadSafeDataTransport.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/ThreadSafeDataTransport.cpp b/third_party/WebKit/Source/platform/graphics/ThreadSafeDataTransport.cpp
index e047a0c2ca5846dbee0b0c09f746bd78051ada69..d082c3bd2a42d060b07bc8204298c169705823c5 100644
--- a/third_party/WebKit/Source/platform/graphics/ThreadSafeDataTransport.cpp
+++ b/third_party/WebKit/Source/platform/graphics/ThreadSafeDataTransport.cpp
@@ -32,7 +32,8 @@
 namespace blink {
 
 ThreadSafeDataTransport::ThreadSafeDataTransport()
-    : m_readBuffer(SharedBuffer::create())
+    : m_newAllDataReceived(false)
+    , m_readBuffer(SharedBuffer::create())
     , m_allDataReceived(false)
     , m_readPosition(0)
 {
@@ -56,7 +57,7 @@ void ThreadSafeDataTransport::setData(SharedBuffer* buffer, bool allDataReceived
     MutexLocker locker(m_mutex);
     m_newBufferQueue.appendVector(newBufferQueue);
     newBufferQueue.clear();
-    m_allDataReceived = allDataReceived;
+    m_newAllDataReceived = allDataReceived;
 }
 
 void ThreadSafeDataTransport::data(SharedBuffer** buffer, bool* allDataReceived)
@@ -67,7 +68,14 @@ void ThreadSafeDataTransport::data(SharedBuffer** buffer, bool* allDataReceived)
     {
         MutexLocker lock(m_mutex);
         m_newBufferQueue.swap(newBufferQueue);
-        *allDataReceived = m_allDataReceived;
+        if (m_allDataReceived && newBufferQueue.size()) {

[aleksandar.stojiljkovic, 2015/12/02 20:33:34]

Nice find. This was handled here, but after ref counting
ThreadSafeDataTransport, it is better to just disable appending data to already
fully downloaded content.

+            // This prevents from unexisting use case now - if alldata was previously
+            // received, don't append but start new buffer and leave reference counting
+            // to handle previous buffer disposal.
+            ASSERT(false);
+            m_readBuffer = SharedBuffer::create();
+        }
+        *allDataReceived = m_allDataReceived = m_newAllDataReceived;
     }
     for (size_t i = 0; i < newBufferQueue.size(); ++i)
         m_readBuffer->append(newBufferQueue[i].get());