Revert "cc: Move canvas clear from picture to picture_pile_impl"

skia/ext/analysis_canvas.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/debug/trace_event.h"
 #include "skia/ext/analysis_canvas.h"
 #include "third_party/skia/include/core/SkDevice.h"
 #include "third_party/skia/include/core/SkDraw.h"
 #include "third_party/skia/include/core/SkRRect.h"
 #include "third_party/skia/include/core/SkShader.h"
@@ skipping 153 matching lines @@
     isSolidColor_ = true;
     color_ = color;
   }
   else {
     isSolidColor_ = false;
   }
 }
 
 void AnalysisDevice::drawPaint(const SkDraw&, const SkPaint& paint) {
   addBitmapFromPaint(paint);
-  isSolidColor_ = false;
+  isSolidColor_ =
+      (isSolidColor_ && isSolidColorPaint(paint) && paint.getColor() == color_);
   isTransparent_ = false;
 }
 
 void AnalysisDevice::drawPoints(const SkDraw&, SkCanvas::PointMode mode,
                           size_t count, const SkPoint[],
                           const SkPaint& paint) {
   addBitmapFromPaint(paint);
   isSolidColor_ = false;
   isTransparent_ = false;
 }
@@ skipping 27 matching lines @@
   else if (paint.getAlpha() != 0 ||
            xferMode != SkXfermode::kSrc_Mode) {
     isTransparent_ = false;
   }
 
   // This bitmap is solid if and only if the following holds.
   // Note that this might be overly conservative:
   // - We're not in "forced not solid" mode
   // - Paint is solid color
   // - The quad is a full tile quad
+  //    - The exception is if the tile is already solid tile,
+  //      and we're drawing the same solid color paint then
+  //      the tile remains solid.

[Tom Hudson, 2013/04/30 09:43:59]

This could be a different CL? But nice catch! Does it show up in practice?

[vmpstr, 2013/04/30 17:06:23]

This shows up on low res tiles. However, with the changes in
picture/picture_pile_impl this might be not necessary for that case. It's good
to keep though, I think :)

The reason it's in the same CL is that it at least _was_ required to fix the bug
in description. I'll have to see if it is still required.

   if (!isForcedNotSolid_ &&
       isSolidColorPaint(paint) &&
-      doesCoverCanvas) {
+      (doesCoverCanvas || (isSolidColor_ && paint.getColor() == color_))) {
     isSolidColor_ = true;
     color_ = paint.getColor();
     hasText_ = false;
   }
   else {
     isSolidColor_ = false;
   }
 }
 
 void AnalysisDevice::drawOval(const SkDraw&, const SkRect& oval,
@@ skipping 220 matching lines @@
     if (savedStackSize_ < forceNotTransparentStackLevel_) {
       (static_cast<AnalysisDevice*>(getDevice()))->setForceNotTransparent(false);
       forceNotTransparentStackLevel_ = kNoLayer;
     }
   }
 }
 
 }  // namespace skia