blimp: Reduce WebP encoding time on the engine.

blimp/engine/renderer/engine_image_serialization_processor.cc

Index: blimp/engine/renderer/engine_image_serialization_processor.cc
diff --git a/blimp/engine/renderer/engine_image_serialization_processor.cc b/blimp/engine/renderer/engine_image_serialization_processor.cc
index 8d1f2bb5f05310f481cd3fab66ac312ee8da584a..b186cdc9be56778d49c003ac870d38ae598090a2 100644
--- a/blimp/engine/renderer/engine_image_serialization_processor.cc
+++ b/blimp/engine/renderer/engine_image_serialization_processor.cc
@@ -67,7 +67,12 @@ class WebPImageEncoder : public SkPixelSerializer {
     // the same as the default configuration for WebP, but since any change in
     // the WebP defaults would invalidate all caches they are hard coded.
     config.quality = 75.0;  // between 0 (smallest file) and 100 (biggest).
-    config.method = 4;  // quality/speed trade-off (0=fast, 6=slower-better).
+
+    // TODO(nyquist): Move image encoding to a different thread when
+    // asynchronous loading of images is possible. The encode work currently
+    // blocks the render thread so we are dropping the method down to 0.
+    // crbug/603643.

[urvang, 2016/04/14 18:52:58]

"crbug.com/603643"

+    config.method = 0;  // quality/speed trade-off (0=fast, 6=slower-better).
 
     // Encode the picture using the given configuration.
     bool success = WebPEncode(&config, &picture);