Revert of Rendering text to a canvas in a frame-less document.

third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2D.cpp

Index: third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2D.cpp
diff --git a/third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2D.cpp b/third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2D.cpp
index 0d09607222a5ee357bcdd1a7f2b296686a736620..57dc2017ba53dfcc12be6ce2242a0c5be90a55db 100644
--- a/third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2D.cpp
+++ b/third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2D.cpp
@@ -376,6 +376,10 @@ SkImageFilter* CanvasRenderingContext2D::stateGetFilter()
 
 void CanvasRenderingContext2D::snapshotStateForFilter()
 {
+    // The style resolution required for fonts is not available in frame-less documents.
+    if (!canvas()->document().frame())
+        return;
+
     modifiableState().setFontForFilter(accessFont());
 }
 
@@ -441,6 +445,10 @@ String CanvasRenderingContext2D::font() const
 
 void CanvasRenderingContext2D::setFont(const String& newFont)
 {
+    // The style resolution required for fonts is not available in frame-less documents.
+    if (!canvas()->document().frame())
+        return;
+
     canvas()->document().updateStyleAndLayoutTreeForNode(canvas());
 
     // The following early exit is dependent on the cache not being empty
@@ -721,6 +729,10 @@ TextMetrics* CanvasRenderingContext2D::measureText(const String& text)
 {
     TextMetrics* metrics = TextMetrics::create();
 
+    // The style resolution required for fonts is not available in frame-less documents.
+    if (!canvas()->document().frame())
+        return metrics;
+
     canvas()->document().updateStyleAndLayoutTreeForNode(canvas());
     const Font& font = accessFont();
 
@@ -762,6 +774,10 @@ TextMetrics* CanvasRenderingContext2D::measureText(const String& text)
 
 void CanvasRenderingContext2D::drawTextInternal(const String& text, double x, double y, CanvasRenderingContext2DState::PaintType paintType, double* maxWidth)
 {
+    // The style resolution required for fonts is not available in frame-less documents.
+    if (!canvas()->document().frame())
+        return;
+
     // accessFont needs the style to be up to date, but updating style can cause script to run,
     // (e.g. due to autofocus) which can free the canvas (set size to 0, for example), so update
     // style before grabbing the drawingCanvas.