Revert 171850

> This patch makes quad-clipping to a scissor window an explicit operation at quad-generation time.  If the transform for the quad is a scale and or a transform clipping is a simple bounding box intersection and uv-recomputation.
> 
> BUG=161871
> 
> 
> Review URL: https://chromiumcodereview.appspot.com/11418297

TBR=whunt@chromium.org
BUG=164997
Review URL: https://codereview.chromium.org/11517007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@172152 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 1 insertions, 52 deletions

diff --git a/cc/texture_draw_quad.cc b/cc/texture_draw_quad.cc
index 97bf86f..d552c39 100644
--- a/cc/texture_draw_quad.cc
+++ b/cc/texture_draw_quad.cc
@@ -58,48 +58,4 @@ const TextureDrawQuad* TextureDrawQuad::MaterialCast(
   return static_cast<const TextureDrawQuad*>(quad);
 }
 
-bool TextureDrawQuad::PerformClipping() {
-  // This only occurs if the rect is only scaled and translated (and thus still
-  // axis aligned).
-  if (!quadTransform().IsScaleOrTranslation())
-    return false;
-
-  // Grab our scale and offset.
-  float x_scale = quadTransform().matrix().getDouble(0,0);
-  float y_scale = quadTransform().matrix().getDouble(1,1);
-  gfx::Vector2dF offset(
-      quadTransform().matrix().getDouble(0,3),
-      quadTransform().matrix().getDouble(1,3));
-
-  // Transform the rect by the scale and offset.
-  gfx::RectF rectF = rect;
-  rectF.Scale(x_scale, y_scale);
-  rectF += offset;
-
-  // Perform clipping and check to see if the result is empty.
-  gfx::RectF clippedRect = IntersectRects(rectF, clipRect());
-  if (clippedRect.IsEmpty()) {
-    rect = gfx::Rect();
-    uv_rect = gfx::RectF();
-    return true;
-  }
-
-  // Create a new uv-rect by clipping the old one to the new bounds.
-  uv_rect = gfx::RectF(
-      uv_rect.x()+uv_rect.width ()/rectF.width ()*(clippedRect.x()-rectF.x()),
-      uv_rect.y()+uv_rect.height()/rectF.height()*(clippedRect.y()-rectF.y()),
-      uv_rect.width () / rectF.width () * clippedRect.width (),
-      uv_rect.height() / rectF.height() * clippedRect.height());
-
-  // Move the clipped rectangle back into its space.
-  clippedRect -= offset;
-  clippedRect.Scale(1.0f / x_scale, 1.0f / y_scale);
-  rect = gfx::Rect(
-      static_cast<int>(clippedRect.x() + 0.5f),
-      static_cast<int>(clippedRect.y() + 0.5f),
-      static_cast<int>(clippedRect.width() + 0.5f),
-      static_cast<int>(clippedRect.height() + 0.5f));
-  return true;
-}
-
 }  // namespace cc
diff --git a/cc/texture_draw_quad.h b/cc/texture_draw_quad.h
index 6ae0e57..177febf 100644
--- a/cc/texture_draw_quad.h
+++ b/cc/texture_draw_quad.h
@@ -40,8 +40,6 @@ class CC_EXPORT TextureDrawQuad : public DrawQuad {
   bool flipped;
 
   static const TextureDrawQuad* MaterialCast(const DrawQuad*);
-
-  bool PerformClipping();
  private:
   TextureDrawQuad();
 };
diff --git a/cc/texture_layer_impl.cc b/cc/texture_layer_impl.cc
index c45aa14..57e06a5 100644
--- a/cc/texture_layer_impl.cc
+++ b/cc/texture_layer_impl.cc
@@ -45,12 +45,7 @@ void TextureLayerImpl::appendQuads(QuadSink& quadSink, AppendQuadsData& appendQu
     gfx::Rect opaqueRect(contentsOpaque() ? quadRect : gfx::Rect());
     scoped_ptr<TextureDrawQuad> quad = TextureDrawQuad::Create();
     quad->SetNew(sharedQuadState, quadRect, opaqueRect, m_externalTextureResource, m_premultipliedAlpha, m_uvRect, m_flipped);
-
-    // Perform explicit clipping on a quad to avoid setting a scissor later.
-    if (sharedQuadState->is_clipped && quad->PerformClipping())
-        sharedQuadState->is_clipped = false;
-    if (!quad->rect.IsEmpty())
-        quadSink.append(quad.PassAs<DrawQuad>(), appendQuadsData);
+    quadSink.append(quad.PassAs<DrawQuad>(), appendQuadsData);
 }
 
 void TextureLayerImpl::didDraw(ResourceProvider* resourceProvider)