Merge 112568 - [chromium] Ensure framebuffer exists at the start of beginDrawingFrame.

Source/WebCore/platform/graphics/chromium/LayerRendererChromium.h

Index: Source/WebCore/platform/graphics/chromium/LayerRendererChromium.h
===================================================================
--- Source/WebCore/platform/graphics/chromium/LayerRendererChromium.h	(revision 112692)
+++ Source/WebCore/platform/graphics/chromium/LayerRendererChromium.h	(working copy)
@@ -61,6 +61,7 @@
 class GeometryBinding;
 class GraphicsContext3D;
 class LayerRendererSwapBuffersCompleteCallbackAdapter;
+class LayerRendererGpuMemoryAllocationChangedCallbackAdapter;
 class ScopedEnsureFramebufferAllocation;
 
 class LayerRendererChromiumClient {
@@ -163,11 +164,12 @@
                           float width, float height, float opacity, const FloatQuad&,
                           int matrixLocation, int alphaLocation, int quadLocation);
 
+protected:
+    friend class LayerRendererGpuMemoryAllocationChangedCallbackAdapter;
     void discardFramebuffer();
     void ensureFramebuffer();
     bool isFramebufferDiscarded() const { return m_isFramebufferDiscarded; }
 
-protected:
     LayerRendererChromium(LayerRendererChromiumClient*, PassRefPtr<GraphicsContext3D>);
     bool initialize();
 
@@ -266,34 +268,7 @@
     bool m_isFramebufferDiscarded;
 };
 
-// The purpose of this helper is twofold:
-// 1. To ensure that a framebuffer is available for scope lifetime, and
-// 2. To reset framebuffer allocation to previous state on scope exit.
-// If the framebuffer is recreated, its contents are undefined.
-// FIXME: Prevent/delay discarding framebuffer via any means while any
-// instance of this is alive. At the moment, this isn't an issue.
-class ScopedEnsureFramebufferAllocation {
-public:
-    explicit ScopedEnsureFramebufferAllocation(LayerRendererChromium* layerRenderer)
-        : m_layerRenderer(layerRenderer)
-        , m_framebufferWasInitiallyDiscarded(layerRenderer->isFramebufferDiscarded())
-    {
-        if (m_framebufferWasInitiallyDiscarded)
-            m_layerRenderer->ensureFramebuffer();
-    }
 
-    ~ScopedEnsureFramebufferAllocation()
-    {
-        if (m_framebufferWasInitiallyDiscarded)
-            m_layerRenderer->discardFramebuffer();
-    }
-
-private:
-    LayerRendererChromium* m_layerRenderer;
-    bool m_framebufferWasInitiallyDiscarded;
-};
-
-
 // Setting DEBUG_GL_CALLS to 1 will call glGetError() after almost every GL
 // call made by the compositor. Useful for debugging rendering issues but
 // will significantly degrade performance.