Bug 547924. Paint <canvas> using EXTEND_PAD to prevent seams. r=vlad

content/canvas/src/nsCanvasRenderingContext2D.cpp

@@ -1030,6 +1030,7 @@ nsCanvasRenderingContext2D::Render(gfxContext *ctx, gfxPattern::GraphicsFilter a
     nsRefPtr<gfxPattern> pat = new gfxPattern(mSurface);
 
     pat->SetFilter(aFilter);
+    pat->SetExtend(gfxPattern::EXTEND_PAD);
 
     gfxContext::GraphicsOperator op = ctx->CurrentOperator();
     if (mOpaque)

gfx/layers/basic/BasicLayers.cpp

@@ -489,6 +489,7 @@ BasicCanvasLayer::Paint(gfxContext* aContext)
   nsRefPtr<gfxPattern> pat = new gfxPattern(mSurface);
 
   pat->SetFilter(mFilter);
+  pat->SetExtend(gfxPattern::EXTEND_PAD);
 
   gfxRect r(0, 0, mBounds.width, mBounds.height);
   gfxMatrix m;