gpu: Remove WebGraphicsContext3D::makeContextCurrent() in Blink

Source/core/html/canvas/WebGLRenderingContextBase.cpp

Index: Source/core/html/canvas/WebGLRenderingContextBase.cpp
diff --git a/Source/core/html/canvas/WebGLRenderingContextBase.cpp b/Source/core/html/canvas/WebGLRenderingContextBase.cpp
index 9946aa3ace7bcb0753ed967da2fa0bc9bb598338..2c4c9d129b7ab43304ff42ecfe3c095bf6c7f5e0 100644
--- a/Source/core/html/canvas/WebGLRenderingContextBase.cpp
+++ b/Source/core/html/canvas/WebGLRenderingContextBase.cpp
@@ -5505,7 +5505,7 @@ void WebGLRenderingContextBase::maybeRestoreContext(Timer<WebGLRenderingContextB
     OwnPtr<blink::WebGraphicsContext3D> context = adoptPtr(blink::Platform::current()->createOffscreenGraphicsContext3D(attributes, 0));
     RefPtr<DrawingBuffer> buffer;
     // Even if a non-null WebGraphicsContext3D is created, until it's made current, it isn't known whether the context is still lost.
-    if (context) {
+    if (context && context->makeContextCurrent()) {

[dshwang, 2014/08/26 18:21:47]

Currently, this code skipped the first makeContextCurrent() after
Platform::createOffscreenGraphicsContext3D(..), but other conservative
makeContextCurrent() call saves it.
Now we need makeContextCurrent() here.

         // Construct a new drawing buffer with the new WebGraphicsContext3D.
         buffer = createDrawingBuffer(context.release());
         // If DrawingBuffer::create() fails to allocate a fbo, |drawingBuffer| is set to null.