Speed up fix for expando-loss conformance test.

third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.h

Index: third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.h
diff --git a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.h b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.h
index 5cdf864c651079ab294c6786dbdaa4ad0dd3db8b..940396936557ee402cc08e081b3bfbe6090646e9 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.h
+++ b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.h
@@ -1039,7 +1039,28 @@ protected:
     // latched into the context's state, or which are implicitly
     // linked together (like programs and their attached shaders), are
     // not garbage collected before they should be.
-    static void preserveObjectWrapper(ScriptState*, ScriptWrappable* sourceObject, const char* baseName, unsigned long index, ScriptWrappable* targetObject);
+    v8::Persistent<v8::Array> m_2DTextureWrappers;
+    v8::Persistent<v8::Array> m_2DArrayTextureWrappers;
+    v8::Persistent<v8::Array> m_3DTextureWrappers;
+    v8::Persistent<v8::Array> m_cubeMapTextureWrappers;
+    v8::Persistent<v8::Array> m_extensionWrappers;

[haraken, 2016/05/13 01:32:41]

Would you help me understand why these persistent handles don't cause leaks?

[Ken Russell (switch to Gerrit), 2016/05/13 01:45:35]

I specifically made them weak to avoid possible leaks. See the call to SetWeak
in WebGLRenderingContextBase::preserveObjectWrapper.

+
+    // The "catch-all" array for the rest of the preserved object
+    // wrappers. The enum below defines how the indices in this array
+    // are used.
+    enum PreservedWrapperIndex {
+        PreservedArrayBuffer,
+        PreservedElementArrayBuffer,
+        PreservedFramebuffer,
+        PreservedProgram,
+        PreservedRenderbuffer,
+        PreservedDefaultVAO,
+        PreservedVAO,
+    };
+    v8::Persistent<v8::Array> m_miscWrappers;
+
+    static void preserveObjectWrapper(ScriptState*, ScriptWrappable* sourceObject, v8::Local<v8::String> hiddenValueName, v8::Persistent<v8::Array>* persistentCache, uint32_t index, ScriptWrappable* targetObject);
+
     // Called to lazily instantiate the wrapper for the default VAO
     // during calls to bindBuffer and vertexAttribPointer (from
     // JavaScript).