Implement HiDPI and pinch-zoom scaling of filter params

cc/output/gl_renderer.cc

 // Copyright 2010 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 "cc/output/gl_renderer.h"
 
 #include <algorithm>
 #include <limits>
 #include <set>
 #include <string>
@@ skipping 615 matching lines @@
 
   // The indices for the line are stored in the same array as the triangle
   // indices.
   GLC(gl_, gl_->DrawElements(GL_LINE_LOOP, 4, GL_UNSIGNED_SHORT, 0));
 }
 
 static SkBitmap ApplyImageFilter(
     scoped_ptr<GLRenderer::ScopedUseGrContext> use_gr_context,
     ResourceProvider* resource_provider,
     const gfx::Point& origin,
+    const gfx::Vector2dF& scale,
     SkImageFilter* filter,
     ScopedResource* source_texture_resource) {
   if (!filter)
     return SkBitmap();
 
   if (!use_gr_context)
     return SkBitmap();
 
   ResourceProvider::ScopedReadLockGL lock(resource_provider,
                                           source_texture_resource->id());
@@ skipping 43 matching lines @@
   skia::RefPtr<SkGpuDevice> device =
       skia::AdoptRef(SkGpuDevice::Create(backing_store->asRenderTarget()));
   DCHECK(device.get());
   SkCanvas canvas(device.get());
 
   // Draw the source bitmap through the filter to the canvas.
   SkPaint paint;
   paint.setImageFilter(filter);
   canvas.clear(SK_ColorTRANSPARENT);
 
-  // TODO(senorblanco): in addition to the origin translation here, the canvas
-  // should also be scaled to accomodate device pixel ratio and pinch zoom. See
-  // crbug.com/281516 and crbug.com/281518.
   canvas.translate(SkIntToScalar(-origin.x()), SkIntToScalar(-origin.y()));
+  canvas.scale(scale.x(), scale.y());
   canvas.drawSprite(source, 0, 0, &paint);
 
   // Flush the GrContext to ensure all buffered GL calls are drawn to the
   // backing store before we access and return it, and have cc begin using the
   // GL context again.
   use_gr_context->context()->flush();
 
   return device->accessBitmap(false);
 }
 
@@ skipping 181 matching lines @@
 
   skia::RefPtr<SkImageFilter> filter = RenderSurfaceFilters::BuildImageFilter(
       quad->background_filters, device_background_texture->size());
 
   SkBitmap filtered_device_background;
   if (apply_background_filters) {
     filtered_device_background =
         ApplyImageFilter(ScopedUseGrContext::Create(this, frame),
                          resource_provider_,
                          quad->rect.origin(),
+                         quad->filters_scale,
                          filter.get(),
                          device_background_texture.get());
   }
   *background_changed = (filtered_device_background.getTexture() != NULL);
 
   int filtered_device_background_texture_id = 0;
   scoped_ptr<ResourceProvider::ScopedReadLockGL> lock;
   if (filtered_device_background.getTexture()) {
     GrTexture* texture =
         reinterpret_cast<GrTexture*>(filtered_device_background.getTexture());
@@ skipping 110 matching lines @@
 
       if (cf && cf->asColorMatrix(color_matrix) && !filter->getInput(0)) {
         // We have a single color matrix as a filter; apply it locally
         // in the compositor.
         use_color_matrix = true;
       } else {
         filter_bitmap =
             ApplyImageFilter(ScopedUseGrContext::Create(this, frame),
                              resource_provider_,
                              quad->rect.origin(),
+                             quad->filters_scale,
                              filter.get(),
                              contents_texture);
       }
     }
   }
 
   if (quad->shared_quad_state->blend_mode != SkXfermode::kSrcOver_Mode &&
       background_texture) {
     filter_bitmap =
         ApplyBlendModeWithBackdrop(ScopedUseGrContext::Create(this, frame),
@@ skipping 2152 matching lines @@
     context_support_->ScheduleOverlayPlane(
         overlay.plane_z_order,
         overlay.transform,
         pending_overlay_resources_.back()->texture_id(),
         overlay.display_rect,
         overlay.uv_rect);
   }
 }
 
 }  // namespace cc