cc: Consolidate the analysis_canvas operations

cc/picture.cc

Index: cc/picture.cc
diff --git a/cc/picture.cc b/cc/picture.cc
index c8fd76ffde70a01830f300dda033c40b37ee4ec9..501621b0668249d3745dc7378e91d98a984a8930 100644
--- a/cc/picture.cc
+++ b/cc/picture.cc
@@ -114,17 +114,23 @@ void Picture::Raster(
   canvas->restore();
 }
 
-bool Picture::IsCheapInRect(const gfx::Rect& layer_rect) const {
-  TRACE_EVENT0("cc", "Picture::IsCheapInRect");
+void Picture::AnalyzeInRect(skia::AnalysisCanvas* canvas,
+                            const gfx::Rect& content_rect,
+                            float contents_scale,
+                            Analysis* analysis) {
+  // Verify the output is valid.
+  DCHECK(analysis);
 
-  SkBitmap emptyBitmap;
-  emptyBitmap.setConfig(SkBitmap::kNo_Config, layer_rect.width(),
-                        layer_rect.height());
-  skia::AnalysisDevice device(emptyBitmap);
-  skia::AnalysisCanvas canvas(&device);
+  canvas->save();
+  canvas->clipRect(gfx::RectToSkRect(content_rect));
+  canvas->scale(contents_scale, contents_scale);
+  canvas->translate(layer_rect_.x(), layer_rect_.y());
+  canvas->drawPicture(*picture_);
+  canvas->restore();
 
-  canvas.drawPicture(*picture_);
-  return canvas.isCheap();
+  analysis->is_solid_color = canvas->getColorIfSolid(&analysis->solid_color);
+  analysis->is_transparent = canvas->isTransparent();
+  analysis->is_cheap_to_raster = canvas->isCheap();
 }
 
 void Picture::GatherPixelRefs(const gfx::Rect& layer_rect,
@@ -155,4 +161,10 @@ void Picture::GatherPixelRefs(const gfx::Rect& layer_rect,
   pixel_refs->unref();
 }
 
+Picture::Analysis::Analysis() :
+    is_solid_color(false),
+    is_transparent(false),
+    is_cheap_to_raster(false) {
+}
+
 }  // namespace cc