Merge 185069 "Enforce context refrence guards in WebGL extensions."

Source/core/html/canvas/ANGLEInstancedArrays.cpp

Index: Source/core/html/canvas/ANGLEInstancedArrays.cpp
===================================================================
--- Source/core/html/canvas/ANGLEInstancedArrays.cpp	(revision 187498)
+++ Source/core/html/canvas/ANGLEInstancedArrays.cpp	(working copy)
@@ -68,26 +68,29 @@
 
 void ANGLEInstancedArrays::drawArraysInstancedANGLE(GLenum mode, GLint first, GLsizei count, GLsizei primcount)
 {
-    if (isLost())
+    WebGLExtensionScopedContext scoped(this);
+    if (scoped.isLost())
         return;
 
-    m_context->drawArraysInstancedANGLE(mode, first, count, primcount);
+    scoped.context()->drawArraysInstancedANGLE(mode, first, count, primcount);
 }
 
 void ANGLEInstancedArrays::drawElementsInstancedANGLE(GLenum mode, GLsizei count, GLenum type, long long offset, GLsizei primcount)
 {
-    if (isLost())
+    WebGLExtensionScopedContext scoped(this);
+    if (scoped.isLost())
         return;
 
-    m_context->drawElementsInstancedANGLE(mode, count, type, offset, primcount);
+    scoped.context()->drawElementsInstancedANGLE(mode, count, type, offset, primcount);
 }
 
 void ANGLEInstancedArrays::vertexAttribDivisorANGLE(GLuint index, GLuint divisor)
 {
-    if (isLost())
+    WebGLExtensionScopedContext scoped(this);
+    if (scoped.isLost())
         return;
 
-    m_context->vertexAttribDivisorANGLE(index, divisor);
+    scoped.context()->vertexAttribDivisorANGLE(index, divisor);
 }
 
 } // namespace blink