Script streaming: fix small script recognition heuristic.

Source/bindings/core/v8/ScriptStreamerTest.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 #include "config.h"
 #include "bindings/core/v8/ScriptStreamer.h"
 
 #include "bindings/core/v8/ScriptSourceCode.h"
 #include "bindings/core/v8/ScriptStreamerThread.h"
@@ skipping 51 matching lines @@
 public:
     ScriptStreamingTest()
         : m_scope(v8::Isolate::GetCurrent())
         , m_settings(Settings::create())
         , m_resourceRequest("http://www.streaming-test.com/")
         , m_resource(new ScriptResource(m_resourceRequest, "text/utf-8"))
         , m_pendingScript(PendingScriptWrapper::create(0, m_resource)) // Takes ownership of m_resource.
     {
         m_settings->setV8ScriptStreamingEnabled(true);
         m_resource->setLoading(true);
-        ScriptStreamer::removeSmallScriptThresholdForTesting();
+        ScriptStreamer::setSmallScriptThresholdForTesting(0);
     }
 
     ScriptState* scriptState() const { return m_scope.scriptState(); }
     v8::Isolate* isolate() const { return m_scope.isolate(); }
 
     PendingScript& pendingScript() const { return m_pendingScript->get(); }
 
 protected:
     void appendData(const char* data)
     {
@@ skipping 188 matching lines @@
     // The finished notification should arrive immediately and not be cycled
     // through a background thread.
     EXPECT_TRUE(client.finished());
 
     bool errorOccurred = false;
     ScriptSourceCode sourceCode = pendingScript().getSource(KURL(), errorOccurred);
     EXPECT_FALSE(errorOccurred);
     EXPECT_FALSE(sourceCode.streamer());
 }
 
+TEST_F(ScriptStreamingTest, SmallScripts)
+{
+    // Small scripts shouldn't be streamed.
+    ScriptStreamer::setSmallScriptThresholdForTesting(100);
+
+    ScriptStreamer::startStreaming(pendingScript(), m_settings.get(), m_scope.scriptState(), PendingScript::ParsingBlocking);
+    TestScriptResourceClient client;
+    pendingScript().watchForLoad(&client);
+
+    appendData("function foo() { }");
+
+    finish();
+
+    // The finished notification should arrive immediately and not be cycled
+    // through a background thread.
+    EXPECT_TRUE(client.finished());
+
+    bool errorOccurred = false;
+    ScriptSourceCode sourceCode = pendingScript().getSource(KURL(), errorOccurred);
+    EXPECT_FALSE(errorOccurred);
+    EXPECT_FALSE(sourceCode.streamer());
+}
+
+TEST_F(ScriptStreamingTest, ScriptsWithSmallFirstChunk)
+{
+    // If a script is long enough, if should be streamed, even if the first data
+    // chunk is small.
+    ScriptStreamer::setSmallScriptThresholdForTesting(100);
+
+    ScriptStreamer::startStreaming(pendingScript(), m_settings.get(), m_scope.scriptState(), PendingScript::ParsingBlocking);
+    TestScriptResourceClient client;
+    pendingScript().watchForLoad(&client);
+
+    // This is the first data chunk which is small.
+    appendData("function foo() { }");
+    appendPadding();
+    appendPadding();
+    appendPadding();
+
+    finish();
+
+    processTasksUntilStreamingComplete();
+    EXPECT_TRUE(client.finished());
+    bool errorOccurred = false;
+    ScriptSourceCode sourceCode = pendingScript().getSource(KURL(), errorOccurred);
+    EXPECT_FALSE(errorOccurred);
+    EXPECT_TRUE(sourceCode.streamer());
+    v8::TryCatch tryCatch;
+    v8::Handle<v8::Script> script = V8ScriptRunner::compileScript(sourceCode, isolate());
+    EXPECT_FALSE(script.IsEmpty());
+    EXPECT_FALSE(tryCatch.HasCaught());
+}
+
 } // namespace
 
 } // namespace blink