Bug 743314 - Force CanUploadSubtextures on Maemo6 harmattan. r=chrislord.net

gfx/gl/GLContext.cpp

@@ -641,6 +641,11 @@ GLContext::CanUploadSubTextures()
     if (!mWorkAroundDriverBugs)
         return true;
 
+    // Lock surface feature allows to mmap texture memory and modify it directly
+    // this feature allow us modify texture partially without full upload
+    if (HasLockSurface())
+        return true;
+
     // There are certain GPUs that we don't want to use glTexSubImage2D on
     // because that function can be very slow and/or buggy
     if (Renderer() == RendererAdreno200 || Renderer() == RendererAdreno205)

gfx/gl/GLContext.h

@@ -731,6 +731,7 @@ public:
     bool CanUploadSubTextures();
     bool CanUploadNonPowerOfTwo();
     bool WantsSmallTiles();
+    virtual bool HasLockSurface() { return false; }
 
     /**
      * If this context wraps a double-buffered target, swap the back

gfx/gl/GLContextProviderEGL.cpp

@@ -597,6 +597,10 @@ public:
         return h;
     }
 
+    virtual bool HasLockSurface() {
+        return sEGLLibrary.HasKHRLockSurface();
+    }
+
 protected:
     friend class GLContextProviderEGL;