Replace WGC3D visibility extension with resource_usage extension. [Part 2 of 3]

content/common/gpu/image_transport_surface_linux.cc

Index: content/common/gpu/image_transport_surface_linux.cc
diff --git a/content/common/gpu/image_transport_surface_linux.cc b/content/common/gpu/image_transport_surface_linux.cc
index 405de3788be88ed2fd3149792036aa9b23e025c0..289202cfc123f2992fb96c1702d1bb83f015ba37 100644
--- a/content/common/gpu/image_transport_surface_linux.cc
+++ b/content/common/gpu/image_transport_surface_linux.cc
@@ -75,7 +75,7 @@ class EGLImageTransportSurface
   virtual gfx::Size GetSize() OVERRIDE;
   virtual bool OnMakeCurrent(gfx::GLContext* context) OVERRIDE;
   virtual unsigned int GetBackingFrameBufferObject() OVERRIDE;
-  virtual void SetVisible(bool visible) OVERRIDE;
+  virtual void SetResourceUsage(ResourceUsage resourceUsage) OVERRIDE;
 
  protected:
   // ImageTransportSurface implementation
@@ -124,7 +124,7 @@ class GLXImageTransportSurface
   virtual std::string GetExtensions();
   virtual gfx::Size GetSize() OVERRIDE;
   virtual bool OnMakeCurrent(gfx::GLContext* context) OVERRIDE;
-  virtual void SetVisible(bool visible) OVERRIDE;
+  virtual void SetResourceUsage(ResourceUsage resourceUsage) OVERRIDE;
 
  protected:
   // ImageTransportSurface implementation:
@@ -312,12 +312,21 @@ unsigned int EGLImageTransportSurface::GetBackingFrameBufferObject() {
   return fbo_id_;
 }
 
-void EGLImageTransportSurface::SetVisible(bool visible) {
-  if (!visible && back_surface_.get() && front_surface_.get()) {
-    ReleaseSurface(&back_surface_);
-  } else if (visible && !back_surface_.get() && front_surface_.get()) {
-    // Leverage the OnResize hook because it does exactly what we want
-    OnResize(front_surface_->size());
+void EGLImageTransportSurface::SetResourceUsage(ResourceUsage resourceUsage) {
+  switch (resourceUsage) {
+    case RESOURCE_USAGE_FULL:
+      if (!back_surface_.get() && front_surface_.get()) {
+        // Leverage the OnResize hook because it does exactly what we want
+        OnResize(front_surface_->size());
+      }
+      break;
+    case RESOURCE_USAGE_LESS:
+      if (back_surface_.get() && front_surface_.get())
+        ReleaseSurface(&back_surface_);
+      break;
+    case RESOURCE_USAGE_NONE:
+      // TODO(mmocny): drop all the buffers
+      break;
   }
 }
 
@@ -509,13 +518,19 @@ void GLXImageTransportSurface::ReleaseSurface() {
   bound_ = false;
 }
 
-void GLXImageTransportSurface::SetVisible(bool visible) {
+void GLXImageTransportSurface::SetResourceUsage(ResourceUsage resourceUsage) {
   Display* dpy = static_cast<Display*>(GetDisplay());
-  if (!visible) {
-    XResizeWindow(dpy, window_, 1, 1);
-  } else {
-    XResizeWindow(dpy, window_, size_.width(), size_.height());
-    needs_resize_ = true;
+  switch (resourceUsage) {
+    case RESOURCE_USAGE_FULL:
+      XResizeWindow(dpy, window_, size_.width(), size_.height());
+      needs_resize_ = true;
+      break;
+    case RESOURCE_USAGE_LESS:
+      XResizeWindow(dpy, window_, 1, 1);
+      break;
+    case RESOURCE_USAGE_NONE:
+      // TODO(mmocny): drop all the buffers
+      break;
   }
   glXWaitX();
 }