Reverting 26975.

Review URL: http://codereview.chromium.org/222011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@26979 0039d316-1c4b-4281-b951-d872f2087c98

9 files changed, 1089 insertions, 81 deletions

diff --git a/skia/ext/convolver.cc b/skia/ext/convolver.cc
index ec0c014..9fe9d3c 100644
--- a/skia/ext/convolver.cc
+++ b/skia/ext/convolver.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2006-2008 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.
 
@@ -112,14 +112,14 @@ class CircularRowBuffer {
 // |src_data| and continues for the num_values() of the filter.
 template<bool has_alpha>
 void ConvolveHorizontally(const unsigned char* src_data,
-                          const ConvolutionFilter1D& filter,
+                          const ConvolusionFilter1D& filter,
                           unsigned char* out_row) {
   // Loop over each pixel on this row in the output image.
   int num_values = filter.num_values();
   for (int out_x = 0; out_x < num_values; out_x++) {
     // Get the filter that determines the current output pixel.
     int filter_offset, filter_length;
-    const ConvolutionFilter1D::Fixed* filter_values =
+    const ConvolusionFilter1D::Fixed* filter_values =
         filter.FilterForValue(out_x, &filter_offset, &filter_length);
 
     // Compute the first pixel in this row that the filter affects. It will
@@ -129,7 +129,7 @@ void ConvolveHorizontally(const unsigned char* src_data,
     // Apply the filter to the row to get the destination pixel in |accum|.
     int accum[4] = {0};
     for (int filter_x = 0; filter_x < filter_length; filter_x++) {
-      ConvolutionFilter1D::Fixed cur_filter = filter_values[filter_x];
+      ConvolusionFilter1D::Fixed cur_filter = filter_values[filter_x];
       accum[0] += cur_filter * row_to_filter[filter_x * 4 + 0];
       accum[1] += cur_filter * row_to_filter[filter_x * 4 + 1];
       accum[2] += cur_filter * row_to_filter[filter_x * 4 + 2];
@@ -139,11 +139,11 @@ void ConvolveHorizontally(const unsigned char* src_data,
 
     // Bring this value back in range. All of the filter scaling factors
     // are in fixed point with kShiftBits bits of fractional part.
-    accum[0] >>= ConvolutionFilter1D::kShiftBits;
-    accum[1] >>= ConvolutionFilter1D::kShiftBits;
-    accum[2] >>= ConvolutionFilter1D::kShiftBits;
+    accum[0] >>= ConvolusionFilter1D::kShiftBits;
+    accum[1] >>= ConvolusionFilter1D::kShiftBits;
+    accum[2] >>= ConvolusionFilter1D::kShiftBits;
     if (has_alpha)
-      accum[3] >>= ConvolutionFilter1D::kShiftBits;
+      accum[3] >>= ConvolusionFilter1D::kShiftBits;
 
     // Store the new pixel.
     out_row[out_x * 4 + 0] = ClampTo8(accum[0]);
@@ -154,19 +154,19 @@ void ConvolveHorizontally(const unsigned char* src_data,
   }
 }
 
-// Does vertical convolution to produce one output row. The filter values and
+// Does vertical convolusion to produce one output row. The filter values and
 // length are given in the first two parameters. These are applied to each
 // of the rows pointed to in the |source_data_rows| array, with each row
 // being |pixel_width| wide.
 //
 // The output must have room for |pixel_width * 4| bytes.
 template<bool has_alpha>
-void ConvolveVertically(const ConvolutionFilter1D::Fixed* filter_values,
+void ConvolveVertically(const ConvolusionFilter1D::Fixed* filter_values,
                         int filter_length,
                         unsigned char* const* source_data_rows,
                         int pixel_width,
                         unsigned char* out_row) {
-  // We go through each column in the output and do a vertical convolution,
+  // We go through each column in the output and do a vertical convolusion,
   // generating one output pixel each time.
   for (int out_x = 0; out_x < pixel_width; out_x++) {
     // Compute the number of bytes over in each row that the current column
@@ -176,7 +176,7 @@ void ConvolveVertically(const ConvolutionFilter1D::Fixed* filter_values,
     // Apply the filter to one column of pixels.
     int accum[4] = {0};
     for (int filter_y = 0; filter_y < filter_length; filter_y++) {
-      ConvolutionFilter1D::Fixed cur_filter = filter_values[filter_y];
+      ConvolusionFilter1D::Fixed cur_filter = filter_values[filter_y];
       accum[0] += cur_filter * source_data_rows[filter_y][byte_offset + 0];
       accum[1] += cur_filter * source_data_rows[filter_y][byte_offset + 1];
       accum[2] += cur_filter * source_data_rows[filter_y][byte_offset + 2];
@@ -186,11 +186,11 @@ void ConvolveVertically(const ConvolutionFilter1D::Fixed* filter_values,
 
     // Bring this value back in range. All of the filter scaling factors
     // are in fixed point with kShiftBits bits of precision.
-    accum[0] >>= ConvolutionFilter1D::kShiftBits;
-    accum[1] >>= ConvolutionFilter1D::kShiftBits;
-    accum[2] >>= ConvolutionFilter1D::kShiftBits;
+    accum[0] >>= ConvolusionFilter1D::kShiftBits;
+    accum[1] >>= ConvolusionFilter1D::kShiftBits;
+    accum[2] >>= ConvolusionFilter1D::kShiftBits;
     if (has_alpha)
-      accum[3] >>= ConvolutionFilter1D::kShiftBits;
+      accum[3] >>= ConvolusionFilter1D::kShiftBits;
 
     // Store the new pixel.
     out_row[byte_offset + 0] = ClampTo8(accum[0]);
@@ -221,9 +221,9 @@ void ConvolveVertically(const ConvolutionFilter1D::Fixed* filter_values,
 
 }  // namespace
 
-// ConvolutionFilter1D ---------------------------------------------------------
+// ConvolusionFilter1D ---------------------------------------------------------
 
-void ConvolutionFilter1D::AddFilter(int filter_offset,
+void ConvolusionFilter1D::AddFilter(int filter_offset,
                                     const float* filter_values,
                                     int filter_length) {
   FilterInstance instance;
@@ -239,7 +239,7 @@ void ConvolutionFilter1D::AddFilter(int filter_offset,
   max_filter_ = std::max(max_filter_, filter_length);
 }
 
-void ConvolutionFilter1D::AddFilter(int filter_offset,
+void ConvolusionFilter1D::AddFilter(int filter_offset,
                                     const Fixed* filter_values,
                                     int filter_length) {
   FilterInstance instance;
@@ -260,8 +260,8 @@ void ConvolutionFilter1D::AddFilter(int filter_offset,
 void BGRAConvolve2D(const unsigned char* source_data,
                     int source_byte_row_stride,
                     bool source_has_alpha,
-                    const ConvolutionFilter1D& filter_x,
-                    const ConvolutionFilter1D& filter_y,
+                    const ConvolusionFilter1D& filter_x,
+                    const ConvolusionFilter1D& filter_y,
                     unsigned char* output) {
   int max_y_filter_size = filter_y.max_filter();
 
@@ -269,22 +269,22 @@ void BGRAConvolve2D(const unsigned char* source_data,
   // convolved row for. If the filter doesn't start at the beginning of the
   // image (this is the case when we are only resizing a subset), then we
   // don't want to generate any output rows before that. Compute the starting
-  // row for convolution as the first pixel for the first vertical filter.
+  // row for convolusion as the first pixel for the first vertical filter.
   int filter_offset, filter_length;
-  const ConvolutionFilter1D::Fixed* filter_values =
+  const ConvolusionFilter1D::Fixed* filter_values =
       filter_y.FilterForValue(0, &filter_offset, &filter_length);
   int next_x_row = filter_offset;
 
-  // We loop over each row in the input doing a horizontal convolution. This
+  // We loop over each row in the input doing a horizontal convolusion. This
   // will result in a horizontally convolved image. We write the results into
-  // a circular buffer of convolved rows and do vertical convolution as rows
+  // a circular buffer of convolved rows and do vertical convolusion as rows
   // are available. This prevents us from having to store the entire
   // intermediate image and helps cache coherency.
   CircularRowBuffer row_buffer(filter_x.num_values(), max_y_filter_size,
                                filter_offset);
 
   // Loop over every possible output row, processing just enough horizontal
-  // convolutions to run each subsequent vertical convolution.
+  // convolusions to run each subsequent vertical convolusion.
   int output_row_byte_width = filter_x.num_values() * 4;
   int num_output_rows = filter_y.num_values();
   for (int out_y = 0; out_y < num_output_rows; out_y++) {
diff --git a/skia/ext/convolver.h b/skia/ext/convolver.h
index 1f38282..91c7ccb 100644
--- a/skia/ext/convolver.h
+++ b/skia/ext/convolver.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2006-2008 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.
 
@@ -18,18 +18,18 @@ namespace skia {
 // object for the filter values contributing to it. You build up the filter
 // list by calling AddFilter for each output pixel (in order).
 //
-// We do 2-dimensional convolution by first convolving each row by one
-// ConvolutionFilter1D, then convolving each column by another one.
+// We do 2-dimensional convolusion by first convolving each row by one
+// ConvolusionFilter1D, then convolving each column by another one.
 //
 // Entries are stored in fixed point, shifted left by kShiftBits.
-class ConvolutionFilter1D {
+class ConvolusionFilter1D {
  public:
   // The number of bits that fixed point values are shifted by.
   enum { kShiftBits = 14 };
 
   typedef short Fixed;
 
-  ConvolutionFilter1D() : max_filter_(0) {
+  ConvolusionFilter1D() : max_filter_(0) {
   }
 
   // Convert between floating point and our fixed point representation.
@@ -106,7 +106,7 @@ class ConvolutionFilter1D {
   int max_filter_;
 };
 
-// Does a two-dimensional convolution on the given source image.
+// Does a two-dimensional convolusion on the given source image.
 //
 // It is assumed the source pixel offsets referenced in the input filters
 // reference only valid pixels, so the source image size is not required. Each
@@ -127,8 +127,8 @@ class ConvolutionFilter1D {
 void BGRAConvolve2D(const unsigned char* source_data,
                     int source_byte_row_stride,
                     bool source_has_alpha,
-                    const ConvolutionFilter1D& xfilter,
-                    const ConvolutionFilter1D& yfilter,
+                    const ConvolusionFilter1D& xfilter,
+                    const ConvolusionFilter1D& yfilter,
                     unsigned char* output);
 
 }  // namespace skia
diff --git a/skia/ext/convolver_unittest.cc b/skia/ext/convolver_unittest.cc
index a25de6e..10db76c 100644
--- a/skia/ext/convolver_unittest.cc
+++ b/skia/ext/convolver_unittest.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2006-2008 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.
 
@@ -14,7 +14,7 @@ namespace skia {
 namespace {
 
 // Fills the given filter with impulse functions for the range 0->num_entries.
-void FillImpulseFilter(int num_entries, ConvolutionFilter1D* filter) {
+void FillImpulseFilter(int num_entries, ConvolusionFilter1D* filter) {
   float one = 1.0f;
   for (int i = 0; i < num_entries; i++)
     filter->AddFilter(i, &one, 1);
@@ -22,13 +22,13 @@ void FillImpulseFilter(int num_entries, ConvolutionFilter1D* filter) {
 
 // Filters the given input with the impulse function, and verifies that it
 // does not change.
-void TestImpulseConvolution(const unsigned char* data, int width, int height) {
+void TestImpulseConvolusion(const unsigned char* data, int width, int height) {
   int byte_count = width * height * 4;
 
-  ConvolutionFilter1D filter_x;
+  ConvolusionFilter1D filter_x;
   FillImpulseFilter(width, &filter_x);
 
-  ConvolutionFilter1D filter_y;
+  ConvolusionFilter1D filter_y;
   FillImpulseFilter(height, &filter_y);
 
   std::vector<unsigned char> output;
@@ -41,7 +41,7 @@ void TestImpulseConvolution(const unsigned char* data, int width, int height) {
 
 // Fills the destination filter with a box filter averaging every two pixels
 // to produce the output.
-void FillBoxFilter(int size, ConvolutionFilter1D* filter) {
+void FillBoxFilter(int size, ConvolusionFilter1D* filter) {
   const float box[2] = { 0.5, 0.5 };
   for (int i = 0; i < size; i++)
     filter->AddFilter(i * 2, box, 2);
@@ -68,7 +68,7 @@ TEST(Convolver, Impulse) {
         input_ptr[(y * width + x) * 4 + channel] = 0xff;
         // Always set the alpha channel or it will attempt to "fix" it for us.
         input_ptr[(y * width + x) * 4 + 3] = 0xff;
-        TestImpulseConvolution(input_ptr, width, height);
+        TestImpulseConvolusion(input_ptr, width, height);
       }
     }
   }
@@ -98,11 +98,11 @@ TEST(Convolver, Halve) {
     input[i] = rand() * 255 / RAND_MAX;
 
   // Compute the filters.
-  ConvolutionFilter1D filter_x, filter_y;
+  ConvolusionFilter1D filter_x, filter_y;
   FillBoxFilter(dest_width, &filter_x);
   FillBoxFilter(dest_height, &filter_y);
 
-  // Do the convolution.
+  // Do the convolusion.
   BGRAConvolve2D(&input[0], src_width, true, filter_x, filter_y, &output[0]);
 
   // Compute the expected results and check, allowing for a small difference
diff --git a/skia/ext/image_operations.cc b/skia/ext/image_operations.cc
index ed4673b..afd7b51 100644
--- a/skia/ext/image_operations.cc
+++ b/skia/ext/image_operations.cc
@@ -1,21 +1,24 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2006-2008 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.
-
+//
 #define _USE_MATH_DEFINES
 #include <cmath>
 #include <limits>
+#include <vector>
 
 #include "skia/ext/image_operations.h"
 
-// TODO(pkasting): skia/ext should not depend on base/!
+#include "base/gfx/rect.h"
+#include "base/gfx/size.h"
 #include "base/histogram.h"
 #include "base/logging.h"
 #include "base/stack_container.h"
 #include "base/time.h"
-#include "skia/ext/convolver.h"
 #include "third_party/skia/include/core/SkBitmap.h"
-#include "third_party/skia/include/core/SkRect.h"
+#include "third_party/skia/include/core/SkColorPriv.h"
+#include "third_party/skia/include/core/SkUnPreMultiply.h"
+#include "skia/ext/convolver.h"
 
 namespace skia {
 
@@ -65,15 +68,15 @@ class ResizeFilter {
   ResizeFilter(ImageOperations::ResizeMethod method,
                int src_full_width, int src_full_height,
                int dest_width, int dest_height,
-               const SkIRect& dest_subset);
+               const gfx::Rect& dest_subset);
 
   // Returns the bounds in the input bitmap of data that is used in the output.
   // The filter offsets are within this rectangle.
-  const SkIRect& src_depend() { return src_depend_; }
+  const gfx::Rect& src_depend() { return src_depend_; }
 
   // Returns the filled filter values.
-  const ConvolutionFilter1D& x_filter() { return x_filter_; }
-  const ConvolutionFilter1D& y_filter() { return y_filter_; }
+  const ConvolusionFilter1D& x_filter() { return x_filter_; }
+  const ConvolusionFilter1D& y_filter() { return y_filter_; }
 
  private:
   // Returns the number of pixels that the filer spans, in filter space (the
@@ -106,7 +109,7 @@ class ResizeFilter {
   void ComputeFilters(int src_size,
                       int dest_subset_lo, int dest_subset_size,
                       float scale, float src_support,
-                      ConvolutionFilter1D* output);
+                      ConvolusionFilter1D* output);
 
   // Computes the filter value given the coordinate in filter space.
   inline float ComputeFilter(float pos) {
@@ -124,7 +127,7 @@ class ResizeFilter {
   ImageOperations::ResizeMethod method_;
 
   // Subset of source the filters will touch.
-  SkIRect src_depend_;
+  gfx::Rect src_depend_;
 
   // Size of the filter support on one side only in the destination space.
   // See GetFilterSupport.
@@ -132,18 +135,18 @@ class ResizeFilter {
   float y_filter_support_;
 
   // Subset of scaled destination bitmap to compute.
-  SkIRect out_bounds_;
+  gfx::Rect out_bounds_;
 
-  ConvolutionFilter1D x_filter_;
-  ConvolutionFilter1D y_filter_;
+  ConvolusionFilter1D x_filter_;
+  ConvolusionFilter1D y_filter_;
 
-  DISALLOW_COPY_AND_ASSIGN(ResizeFilter);
+  DISALLOW_EVIL_CONSTRUCTORS(ResizeFilter);
 };
 
 ResizeFilter::ResizeFilter(ImageOperations::ResizeMethod method,
                            int src_full_width, int src_full_height,
                            int dest_width, int dest_height,
-                           const SkIRect& dest_subset)
+                           const gfx::Rect& dest_subset)
     : method_(method),
       out_bounds_(dest_subset) {
   float scale_x = static_cast<float>(dest_width) /
@@ -154,24 +157,25 @@ ResizeFilter::ResizeFilter(ImageOperations::ResizeMethod method,
   x_filter_support_ = GetFilterSupport(scale_x);
   y_filter_support_ = GetFilterSupport(scale_y);
 
-  SkIRect src_full = { 0, 0, src_full_width, src_full_height };
-  SkIRect dest_full = { 0, 0, static_cast<int>(src_full_width * scale_x + 0.5),
-                        static_cast<int>(src_full_height * scale_y + 0.5) };
+  gfx::Rect src_full(0, 0, src_full_width, src_full_height);
+  gfx::Rect dest_full(0, 0,
+                      static_cast<int>(src_full_width * scale_x + 0.5),
+                      static_cast<int>(src_full_height * scale_y + 0.5));
 
   // Support of the filter in source space.
   float src_x_support = x_filter_support_ / scale_x;
   float src_y_support = y_filter_support_ / scale_y;
 
-  ComputeFilters(src_full_width, dest_subset.fLeft, dest_subset.width(),
+  ComputeFilters(src_full_width, dest_subset.x(), dest_subset.width(),
                  scale_x, src_x_support, &x_filter_);
-  ComputeFilters(src_full_height, dest_subset.fTop, dest_subset.height(),
+  ComputeFilters(src_full_height, dest_subset.y(), dest_subset.height(),
                  scale_y, src_y_support, &y_filter_);
 }
 
 void ResizeFilter::ComputeFilters(int src_size,
                                   int dest_subset_lo, int dest_subset_size,
                                   float scale, float src_support,
-                                  ConvolutionFilter1D* output) {
+                                  ConvolusionFilter1D* output) {
   int dest_subset_hi = dest_subset_lo + dest_subset_size;  // [lo, hi)
 
   // When we're doing a magnification, the scale will be larger than one. This
@@ -255,12 +259,11 @@ void ResizeFilter::ComputeFilters(int src_size,
 SkBitmap ImageOperations::Resize(const SkBitmap& source,
                                  ResizeMethod method,
                                  int dest_width, int dest_height,
-                                 const SkIRect& dest_subset) {
+                                 const gfx::Rect& dest_subset) {
   // Time how long this takes to see if it's a problem for users.
   base::TimeTicks resize_start = base::TimeTicks::Now();
 
-  SkIRect dest = { 0, 0, dest_width, dest_height };
-  DCHECK(dest.contains(dest_subset)) <<
+  DCHECK(gfx::Rect(dest_width, dest_height).Contains(dest_subset)) <<
       "The supplied subset does not fall within the destination image.";
 
   // If the size of source or destination is 0, i.e. 0x0, 0xN or Nx0, just
@@ -302,9 +305,361 @@ SkBitmap ImageOperations::Resize(const SkBitmap& source,
 SkBitmap ImageOperations::Resize(const SkBitmap& source,
                                  ResizeMethod method,
                                  int dest_width, int dest_height) {
-  SkIRect dest_subset = { 0, 0, dest_width, dest_height };
+  gfx::Rect dest_subset(0, 0, dest_width, dest_height);
   return Resize(source, method, dest_width, dest_height, dest_subset);
 }
 
+// static
+SkBitmap ImageOperations::CreateBlendedBitmap(const SkBitmap& first,
+                                              const SkBitmap& second,
+                                              double alpha) {
+  DCHECK(alpha <= 1 && alpha >= 0);
+  DCHECK(first.width() == second.width());
+  DCHECK(first.height() == second.height());
+  DCHECK(first.bytesPerPixel() == second.bytesPerPixel());
+  DCHECK(first.config() == SkBitmap::kARGB_8888_Config);
+
+  // Optimize for case where we won't need to blend anything.
+  static const double alpha_min = 1.0 / 255;
+  static const double alpha_max = 254.0 / 255;
+  if (alpha < alpha_min)
+    return first;
+  else if (alpha > alpha_max)
+    return second;
+
+  SkAutoLockPixels lock_first(first);
+  SkAutoLockPixels lock_second(second);
+
+  SkBitmap blended;
+  blended.setConfig(SkBitmap::kARGB_8888_Config, first.width(),
+                    first.height(), 0);
+  blended.allocPixels();
+  blended.eraseARGB(0, 0, 0, 0);
+
+  double first_alpha = 1 - alpha;
+
+  for (int y = 0; y < first.height(); y++) {
+    uint32* first_row = first.getAddr32(0, y);
+    uint32* second_row = second.getAddr32(0, y);
+    uint32* dst_row = blended.getAddr32(0, y);
+
+    for (int x = 0; x < first.width(); x++) {
+      uint32 first_pixel = first_row[x];
+      uint32 second_pixel = second_row[x];
+
+      int a = static_cast<int>(
+          SkColorGetA(first_pixel) * first_alpha +
+          SkColorGetA(second_pixel) * alpha);
+      int r = static_cast<int>(
+          SkColorGetR(first_pixel) * first_alpha +
+          SkColorGetR(second_pixel) * alpha);
+      int g = static_cast<int>(
+          SkColorGetG(first_pixel) * first_alpha +
+          SkColorGetG(second_pixel) * alpha);
+      int b = static_cast<int>(
+          SkColorGetB(first_pixel) * first_alpha +
+          SkColorGetB(second_pixel) * alpha);
+
+      dst_row[x] = SkColorSetARGB(a, r, g, b);
+    }
+  }
+
+  return blended;
+}
+
+// static
+SkBitmap ImageOperations::CreateMaskedBitmap(const SkBitmap& rgb,
+                                             const SkBitmap& alpha) {
+  DCHECK(rgb.width() == alpha.width());
+  DCHECK(rgb.height() == alpha.height());
+  DCHECK(rgb.bytesPerPixel() == alpha.bytesPerPixel());
+  DCHECK(rgb.config() == SkBitmap::kARGB_8888_Config);
+  DCHECK(alpha.config() == SkBitmap::kARGB_8888_Config);
+
+  SkBitmap masked;
+  masked.setConfig(SkBitmap::kARGB_8888_Config, rgb.width(), rgb.height(), 0);
+  masked.allocPixels();
+  masked.eraseARGB(0, 0, 0, 0);
+
+  SkAutoLockPixels lock_rgb(rgb);
+  SkAutoLockPixels lock_alpha(alpha);
+  SkAutoLockPixels lock_masked(masked);
+
+  for (int y = 0; y < masked.height(); y++) {
+    uint32* rgb_row = rgb.getAddr32(0, y);
+    uint32* alpha_row = alpha.getAddr32(0, y);
+    uint32* dst_row = masked.getAddr32(0, y);
+
+    for (int x = 0; x < masked.width(); x++) {
+      uint32 alpha_pixel = alpha_row[x];
+      SkColor rgb_pixel = SkUnPreMultiply::PMColorToColor(rgb_row[x]);
+
+      int alpha = SkAlphaMul(SkColorGetA(rgb_pixel), SkColorGetA(alpha_pixel));
+      dst_row[x] = SkColorSetARGB(alpha,
+                                  SkAlphaMul(SkColorGetR(rgb_pixel), alpha),
+                                  SkAlphaMul(SkColorGetG(rgb_pixel), alpha),
+                                  SkAlphaMul(SkColorGetB(rgb_pixel), alpha));
+    }
+  }
+
+  return masked;
+}
+
+// static
+SkBitmap ImageOperations::CreateButtonBackground(SkColor color,
+                                                 const SkBitmap& image,
+                                                 const SkBitmap& mask) {
+  DCHECK(image.config() == SkBitmap::kARGB_8888_Config);
+  DCHECK(mask.config() == SkBitmap::kARGB_8888_Config);
+
+  SkBitmap background;
+  background.setConfig(SkBitmap::kARGB_8888_Config,
+                       mask.width(),
+                       mask.height(), 0);
+  background.allocPixels();
+
+  int bg_a = SkColorGetA(color);
+  int bg_r = SkColorGetR(color);
+  int bg_g = SkColorGetG(color);
+  int bg_b = SkColorGetB(color);
+
+  SkAutoLockPixels lock_mask(mask);
+  SkAutoLockPixels lock_image(image);
+  SkAutoLockPixels lock_background(background);
+
+  for (int y = 0; y < mask.height(); y++) {
+    uint32* dst_row = background.getAddr32(0, y);
+    uint32* image_row = image.getAddr32(0, y % image.height());
+    uint32* mask_row = mask.getAddr32(0, y);
+
+    for (int x = 0; x < mask.width(); x++) {
+      uint32 mask_pixel = mask_row[x];
+      uint32 image_pixel = image_row[x % image.width()];
+
+      int img_a = SkColorGetA(image_pixel);
+      int img_r = SkColorGetR(image_pixel);
+      int img_g = SkColorGetG(image_pixel);
+      int img_b = SkColorGetB(image_pixel);
+
+      double img_alpha = static_cast<double>(img_a) / 255.0;
+      double img_inv = 1 - img_alpha;
+
+      double mask_a = static_cast<double>(SkColorGetA(mask_pixel)) / 255.0;
+
+      dst_row[x] = SkColorSetARGB(
+          static_cast<int>(std::min(255, bg_a + img_a) * mask_a),
+          static_cast<int>((bg_r * img_inv + img_r * img_alpha) * mask_a),
+          static_cast<int>((bg_g * img_inv + img_g * img_alpha) * mask_a),
+          static_cast<int>((bg_b * img_inv + img_b * img_alpha) * mask_a));
+    }
+  }
+
+  return background;
+}
+
+
+SkBitmap ImageOperations::CreateBlurredBitmap(const SkBitmap& bitmap,
+                                              int blur_amount ) {
+  DCHECK(bitmap.config() == SkBitmap::kARGB_8888_Config);
+
+  // Blur factor (1 divided by how many pixels the blur takes place over).
+  double v = 1.0 / pow(static_cast<double>(blur_amount * 2 + 1), 2);
+
+  SkBitmap blurred;
+  blurred.setConfig(SkBitmap::kARGB_8888_Config, bitmap.width(),
+                    bitmap.height(), 0);
+  blurred.allocPixels();
+  blurred.eraseARGB(0, 0, 0, 0);
+
+  SkAutoLockPixels lock_bitmap(bitmap);
+  SkAutoLockPixels lock_blurred(blurred);
+
+  // Loop through every pixel in the image.
+  for (int y = 0; y < bitmap.height(); y++) {  // Skip top and bottom edges.
+    uint32* dst_row = blurred.getAddr32(0, y);
+
+    for (int x = 0; x < bitmap.width(); x++) {  // Skip left and right edges.
+      // Sums for this pixel.
+      double a = 0;
+      double r = 0;
+      double g = 0;
+      double b = 0;
+
+      for (int ky = -blur_amount; ky <= blur_amount; ky++) {
+        for (int kx = -blur_amount; kx <= blur_amount; kx++) {
+          // Calculate the adjacent pixel for this kernel point. Blurs
+          // are wrapped.
+          int bx = (x + kx) % bitmap.width();
+          while (bx < 0)
+            bx += bitmap.width();
+          int by = (y + ky) % bitmap.height();
+          while (by < 0)
+            by += bitmap.height();
+
+          uint32 src_pixel = bitmap.getAddr32(0, by)[bx];
+
+          a += v * static_cast<double>(SkColorGetA(src_pixel));
+          r += v * static_cast<double>(SkColorGetR(src_pixel));
+          g += v * static_cast<double>(SkColorGetG(src_pixel));
+          b += v * static_cast<double>(SkColorGetB(src_pixel));
+        }
+      }
+
+      dst_row[x] = SkColorSetARGB(
+          static_cast<int>(a),
+          static_cast<int>(r),
+          static_cast<int>(g),
+          static_cast<int>(b));
+    }
+  }
+
+  return blurred;
+}
+
+// static
+SkBitmap ImageOperations::CreateHSLShiftedBitmap(const SkBitmap& bitmap,
+                                                 HSL hsl_shift) {
+  DCHECK(bitmap.empty() == false);
+  DCHECK(bitmap.config() == SkBitmap::kARGB_8888_Config);
+
+  SkBitmap shifted;
+  shifted.setConfig(SkBitmap::kARGB_8888_Config, bitmap.width(),
+                    bitmap.height(), 0);
+  shifted.allocPixels();
+  shifted.eraseARGB(0, 0, 0, 0);
+  shifted.setIsOpaque(false);
+
+  SkAutoLockPixels lock_bitmap(bitmap);
+  SkAutoLockPixels lock_shifted(shifted);
+
+  // Loop through the pixels of the original bitmap.
+  for (int y = 0; y < bitmap.height(); y++) {
+    SkPMColor* pixels = bitmap.getAddr32(0, y);
+    SkPMColor* tinted_pixels = shifted.getAddr32(0, y);
+
+    for (int x = 0; x < bitmap.width(); x++) {
+      SkColor color = SkUnPreMultiply::PMColorToColor(pixels[x]);
+      SkColor shifted = HSLShift(color, hsl_shift);
+      tinted_pixels[x] = SkPreMultiplyColor(shifted);
+    }
+  }
+
+  return shifted;
+}
+
+// static
+SkBitmap ImageOperations::CreateTiledBitmap(const SkBitmap& source,
+                                            int src_x, int src_y,
+                                            int dst_w, int dst_h) {
+  DCHECK(source.getConfig() == SkBitmap::kARGB_8888_Config);
+
+  SkBitmap cropped;
+  cropped.setConfig(SkBitmap::kARGB_8888_Config, dst_w, dst_h, 0);
+  cropped.allocPixels();
+  cropped.eraseARGB(0, 0, 0, 0);
+
+  SkAutoLockPixels lock_source(source);
+  SkAutoLockPixels lock_cropped(cropped);
+
+  // Loop through the pixels of the original bitmap.
+  for (int y = 0; y < dst_h; y++) {
+    int y_pix = (src_y + y) % source.height();
+    while (y_pix < 0)
+      y_pix += source.height();
+
+    uint32* source_row = source.getAddr32(0, y_pix);
+    uint32* dst_row = cropped.getAddr32(0, y);
+
+    for (int x = 0; x < dst_w; x++) {
+      int x_pix = (src_x + x) % source.width();
+      while (x_pix < 0)
+        x_pix += source.width();
+
+      dst_row[x] = source_row[x_pix];
+    }
+  }
+
+  return cropped;
+}
+
+// static
+SkBitmap ImageOperations::DownsampleByTwo(const SkBitmap& bitmap) {
+  // Handle the nop case.
+  if (bitmap.width() <= 1 || bitmap.height() <= 1)
+    return bitmap;
+
+  SkBitmap result;
+  result.setConfig(SkBitmap::kARGB_8888_Config,
+                   (bitmap.width() + 1) / 2,
+                   (bitmap.height() + 1) / 2);
+  result.allocPixels();
+
+  SkAutoLockPixels lock(bitmap);
+  for (int dest_y = 0; dest_y < result.height(); dest_y++) {
+    for (int dest_x = 0; dest_x < result.width(); dest_x++ ) {
+      // This code is based on downsampleby2_proc32 in SkBitmap.cpp. It is very
+      // clever in that it does two channels at once: alpha and green ("ag")
+      // and red and blue ("rb"). Each channel gets averaged across 4 pixels
+      // to get the result.
+      int src_x = dest_x << 1;
+      int src_y = dest_y << 1;
+      const SkPMColor* cur_src = bitmap.getAddr32(src_x, src_y);
+      SkPMColor tmp, ag, rb;
+
+      // Top left pixel of the 2x2 block.
+      tmp = *cur_src;
+      ag = (tmp >> 8) & 0xFF00FF;
+      rb = tmp & 0xFF00FF;
+      if (src_x < bitmap.width() - 1)
+        cur_src += 1;
+
+      // Top right pixel of the 2x2 block.
+      tmp = *cur_src;
+      ag += (tmp >> 8) & 0xFF00FF;
+      rb += tmp & 0xFF00FF;
+      if (src_y < bitmap.height() - 1)
+        cur_src = bitmap.getAddr32(src_x, src_y + 1);
+      else
+        cur_src = bitmap.getAddr32(src_x, src_y);  // Move back to the first.
+
+      // Bottom left pixel of the 2x2 block.
+      tmp = *cur_src;
+      ag += (tmp >> 8) & 0xFF00FF;
+      rb += tmp & 0xFF00FF;
+      if (src_x < bitmap.width() - 1)
+        cur_src += 1;
+
+      // Bottom right pixel of the 2x2 block.
+      tmp = *cur_src;
+      ag += (tmp >> 8) & 0xFF00FF;
+      rb += tmp & 0xFF00FF;
+
+      // Put the channels back together, dividing each by 4 to get the average.
+      // |ag| has the alpha and green channels shifted right by 8 bits from
+      // there they should end up, so shifting left by 6 gives them in the
+      // correct position divided by 4.
+      *result.getAddr32(dest_x, dest_y) =
+          ((rb >> 2) & 0xFF00FF) | ((ag << 6) & 0xFF00FF00);
+    }
+  }
+
+  return result;
+}
+
+// static
+SkBitmap ImageOperations::DownsampleByTwoUntilSize(const SkBitmap& bitmap,
+                                                   int min_w, int min_h) {
+  if (bitmap.width() <= min_w || bitmap.height() <= min_h ||
+      min_w < 0 || min_h < 0)
+    return bitmap;
+
+  // Since bitmaps are refcounted, this copy will be fast.
+  SkBitmap current = bitmap;
+  while (current.width() >= min_w * 2 && current.height() >= min_h * 2 &&
+         current.width() > 1 && current.height() > 1)
+    current = DownsampleByTwo(current);
+  return current;
+}
+
 }  // namespace skia
 
diff --git a/skia/ext/image_operations.h b/skia/ext/image_operations.h
index e9f448b..3b172c8 100644
--- a/skia/ext/image_operations.h
+++ b/skia/ext/image_operations.h
@@ -1,12 +1,16 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2006-2008 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.
 
 #ifndef SKIA_EXT_IMAGE_OPERATIONS_H_
 #define SKIA_EXT_IMAGE_OPERATIONS_H_
 
+#include "base/basictypes.h"
+#include "base/gfx/rect.h"
+#include "skia/ext/skia_utils.h"
+#include "third_party/skia/include/core/SkColor.h"
+
 class SkBitmap;
-struct SkIRect;
 
 namespace skia {
 
@@ -36,7 +40,7 @@ class ImageOperations {
   static SkBitmap Resize(const SkBitmap& source,
                          ResizeMethod method,
                          int dest_width, int dest_height,
-                         const SkIRect& dest_subset);
+                         const gfx::Rect& dest_subset);
 
   // Alternate version for resizing and returning the entire bitmap rather than
   // a subset.
@@ -44,6 +48,69 @@ class ImageOperations {
                          ResizeMethod method,
                          int dest_width, int dest_height);
 
+  // Create a bitmap that is a blend of two others. The alpha argument
+  // specifies the opacity of the second bitmap. The provided bitmaps must
+  // use have the kARGB_8888_Config config and be of equal dimensions.
+  static SkBitmap CreateBlendedBitmap(const SkBitmap& first,
+                                      const SkBitmap& second,
+                                      double alpha);
+
+  // Create a bitmap that is the original bitmap masked out by the mask defined
+  // in the alpha bitmap. The images must use the kARGB_8888_Config config and
+  // be of equal dimensions.
+  static SkBitmap CreateMaskedBitmap(const SkBitmap& first,
+                                     const SkBitmap& alpha);
+
+  // We create a button background image by compositing the color and image
+  // together, then applying the mask. This is a highly specialized composite
+  // operation that is the equivalent of drawing a background in |color|,
+  // tiling |image| over the top, and then masking the result out with |mask|.
+  // The images must use kARGB_8888_Config config.
+  static SkBitmap CreateButtonBackground(SkColor color,
+                                         const SkBitmap& image,
+                                         const SkBitmap& mask);
+
+  // Blur a bitmap using an average-blur algorithm over the rectangle defined
+  // by |blur_amount|. The blur will wrap around image edges.
+  static SkBitmap CreateBlurredBitmap(const SkBitmap& bitmap, int blur_amount);
+
+  // Shift a bitmap's HSL values. The shift values are in the range of 0-1,
+  // with the option to specify -1 for 'no change'. The shift values are
+  // defined as:
+  // hsl_shift[0] (hue): The absolute hue value for the image - 0 and 1 map
+  //    to 0 and 360 on the hue color wheel (red).
+  // hsl_shift[1] (saturation): A saturation shift for the image, with the
+  //    following key values:
+  //    0 = remove all color.
+  //    0.5 = leave unchanged.
+  //    1 = fully saturate the image.
+  // hsl_shift[2] (lightness): A lightness shift for the image, with the
+  //    following key values:
+  //    0 = remove all lightness (make all pixels black).
+  //    0.5 = leave unchanged.
+  //    1 = full lightness (make all pixels white).
+  static SkBitmap CreateHSLShiftedBitmap(const SkBitmap& bitmap,
+                                         HSL hsl_shift);
+
+  // Create a bitmap that is cropped from another bitmap. This is special
+  // because it tiles the original bitmap, so your coordinates can extend
+  // outside the bounds of the original image.
+  static SkBitmap CreateTiledBitmap(const SkBitmap& bitmap,
+                                    int src_x, int src_y,
+                                    int dst_w, int dst_h);
+
+  // Makes a bitmap half has large in each direction by averaging groups of
+  // 4 pixels. This is one step in generating a mipmap.
+  static SkBitmap DownsampleByTwo(const SkBitmap& bitmap);
+
+  // Iteratively downsamples by 2 until the bitmap is no smaller than the
+  // input size. The normal use of this is to downsample the bitmap "close" to
+  // the final size, and then use traditional resampling on the result.
+  // Because the bitmap will be closer to the final size, it will be faster,
+  // and linear interpolation will generally work well as a second step.
+  static SkBitmap DownsampleByTwoUntilSize(const SkBitmap& bitmap,
+                                           int min_w, int min_h);
+
  private:
   ImageOperations();  // Class for scoping only.
 };
diff --git a/skia/ext/image_operations_unittest.cc b/skia/ext/image_operations_unittest.cc
index 52d13b9..dbf4fce 100644
--- a/skia/ext/image_operations_unittest.cc
+++ b/skia/ext/image_operations_unittest.cc
@@ -1,11 +1,14 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2006-2008 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 <stdlib.h>
+
 #include "skia/ext/image_operations.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkBitmap.h"
-#include "third_party/skia/include/core/SkRect.h"
+#include "third_party/skia/include/core/SkColorPriv.h"
+#include "third_party/skia/include/core/SkUnPreMultiply.h"
 
 namespace {
 
@@ -102,7 +105,7 @@ TEST(ImageOperations, HalveSubset) {
 
   // Now do a halving of a a subset, recall the destination subset is in the
   // destination coordinate system (max = half of the original image size).
-  SkIRect subset_rect = { 2, 3, 3, 6 };
+  gfx::Rect subset_rect(2, 3, 3, 6);
   SkBitmap subset_results = skia::ImageOperations::Resize(
       src, skia::ImageOperations::RESIZE_BOX,
       src_w / 2, src_h / 2, subset_rect);
@@ -116,7 +119,7 @@ TEST(ImageOperations, HalveSubset) {
   for (int y = 0; y < subset_rect.height(); y++) {
     for (int x = 0; x < subset_rect.width(); x++) {
       ASSERT_EQ(
-          *full_results.getAddr32(x + subset_rect.fLeft, y + subset_rect.fTop),
+          *full_results.getAddr32(x + subset_rect.x(), y + subset_rect.y()),
           *subset_results.getAddr32(x, y));
     }
   }
@@ -144,3 +147,372 @@ TEST(ImageOperations, ResampleToSame) {
     }
   }
 }
+
+// Blend two bitmaps together at 50% alpha and verify that the result
+// is the middle-blend of the two.
+TEST(ImageOperations, CreateBlendedBitmap) {
+  int src_w = 16, src_h = 16;
+  SkBitmap src_a;
+  src_a.setConfig(SkBitmap::kARGB_8888_Config, src_w, src_h);
+  src_a.allocPixels();
+
+  SkBitmap src_b;
+  src_b.setConfig(SkBitmap::kARGB_8888_Config, src_w, src_h);
+  src_b.allocPixels();
+
+  for (int y = 0, i = 0; y < src_h; y++) {
+    for (int x = 0; x < src_w; x++) {
+      *src_a.getAddr32(x, y) = SkColorSetARGB(255, 0, i * 2 % 255, i % 255);
+      *src_b.getAddr32(x, y) =
+          SkColorSetARGB((255 - i) % 255, i % 255, i * 4 % 255, 0);
+      i++;
+    }
+  }
+
+  // Shift to red.
+  SkBitmap blended = skia::ImageOperations::CreateBlendedBitmap(
+    src_a, src_b, 0.5);
+  SkAutoLockPixels srca_lock(src_a);
+  SkAutoLockPixels srcb_lock(src_b);
+  SkAutoLockPixels blended_lock(blended);
+
+  for (int y = 0; y < src_h; y++) {
+    for (int x = 0; x < src_w; x++) {
+      int i = y * src_w + x;
+      EXPECT_EQ(static_cast<unsigned int>((255 + ((255 - i) % 255)) / 2),
+                SkColorGetA(*blended.getAddr32(x, y)));
+      EXPECT_EQ(static_cast<unsigned int>(i % 255 / 2),
+                SkColorGetR(*blended.getAddr32(x, y)));
+      EXPECT_EQ((static_cast<unsigned int>((i * 2) % 255 + (i * 4) % 255) / 2),
+                SkColorGetG(*blended.getAddr32(x, y)));
+      EXPECT_EQ(static_cast<unsigned int>(i % 255 / 2),
+                SkColorGetB(*blended.getAddr32(x, y)));
+    }
+  }
+}
+
+// Test our masking functions.
+TEST(ImageOperations, CreateMaskedBitmap) {
+  int src_w = 16, src_h = 16;
+
+  SkBitmap src;
+  FillDataToBitmap(src_w, src_h, &src);
+
+  // Generate alpha mask
+  SkBitmap alpha;
+  alpha.setConfig(SkBitmap::kARGB_8888_Config, src_w, src_h);
+  alpha.allocPixels();
+  for (int y = 0, i = 0; y < src_h; y++) {
+    for (int x = 0; x < src_w; x++) {
+      *alpha.getAddr32(x, y) = SkColorSetARGB((i + 128) % 255,
+                                              (i + 128) % 255,
+                                              (i + 64) % 255,
+                                              (i + 0) % 255);
+      i++;
+    }
+  }
+
+  SkBitmap masked = skia::ImageOperations::CreateMaskedBitmap(src, alpha);
+
+  SkAutoLockPixels src_lock(src);
+  SkAutoLockPixels alpha_lock(alpha);
+  SkAutoLockPixels masked_lock(masked);
+  for (int y = 0; y < src_h; y++) {
+    for (int x = 0; x < src_w; x++) {
+      // Test that the alpha is equal.
+      SkColor src_pixel = SkUnPreMultiply::PMColorToColor(*src.getAddr32(x, y));
+      SkColor alpha_pixel =
+          SkUnPreMultiply::PMColorToColor(*alpha.getAddr32(x, y));
+      SkColor masked_pixel = *masked.getAddr32(x, y);
+
+      int alpha_value = SkAlphaMul(SkColorGetA(src_pixel),
+                                   SkColorGetA(alpha_pixel));
+      SkColor expected_pixel = SkColorSetARGB(
+          alpha_value,
+          SkAlphaMul(SkColorGetR(src_pixel), alpha_value),
+          SkAlphaMul(SkColorGetG(src_pixel), alpha_value),
+          SkAlphaMul(SkColorGetB(src_pixel), alpha_value));
+
+      EXPECT_TRUE(ColorsClose(expected_pixel, masked_pixel));
+    }
+  }
+}
+
+// Testing blur without reimplementing the blur algorithm here is tough,
+// so we just check to see if the pixels have moved in the direction we
+// think they should move in (and also checking the wrapping behavior).
+// This will allow us to tweak the blur algorithm to suit speed/visual
+// needs without breaking the fundamentals.
+TEST(ImageOperations, CreateBlurredBitmap) {
+  int src_w = 4, src_h = 4;
+  SkBitmap src;
+  src.setConfig(SkBitmap::kARGB_8888_Config, src_w, src_h);
+  src.allocPixels();
+
+  for (int y = 0, i = 0; y < src_h; y++) {
+    for (int x = 0; x < src_w; x++) {
+      int r = (y == 0) ? 255 : 0;  // Make the top row red.
+      int g = (i % 2 == 0) ? 255 : 0;  // Make green alternate in each pixel.
+      int b = (y == src_h - 1) ? 255 : 0;  // Make the bottom row blue.
+
+      *src.getAddr32(x, y) = SkColorSetARGB(255, r, g, b);
+      i++;
+    }
+  }
+
+  // Perform a small blur (enough to shove the values in the direction we
+  // need - more would just be an unneccessary unit test slowdown).
+  SkBitmap blurred = skia::ImageOperations::CreateBlurredBitmap(src, 2);
+
+  SkAutoLockPixels src_lock(src);
+  SkAutoLockPixels blurred_lock(blurred);
+  for (int y = 0, i = 0; y < src_w; y++) {
+    for (int x = 0; x < src_h; x++) {
+      SkColor src_pixel = *src.getAddr32(x, y);
+      SkColor blurred_pixel = *blurred.getAddr32(x, y);
+      if (y == 0) {
+        // We expect our red to have decreased, but our blue to have
+        // increased (from the wrapping from the bottom line).
+        EXPECT_TRUE(SkColorGetR(blurred_pixel) < SkColorGetR(src_pixel));
+        EXPECT_TRUE(SkColorGetB(blurred_pixel) > SkColorGetB(src_pixel));
+      } else if (y == src_h - 1) {
+        // Now for the opposite.
+        EXPECT_TRUE(SkColorGetB(blurred_pixel) < SkColorGetB(src_pixel));
+        EXPECT_TRUE(SkColorGetR(blurred_pixel) > SkColorGetR(src_pixel));
+      }
+
+      // Expect the green channel to have moved towards the center (but
+      // not past it).
+      if (i % 2 == 0) {
+        EXPECT_LT(SkColorGetG(blurred_pixel), SkColorGetG(src_pixel));
+        EXPECT_GE(SkColorGetG(blurred_pixel), static_cast<uint32>(128));
+      } else {
+        EXPECT_GT(SkColorGetG(blurred_pixel), SkColorGetG(src_pixel));
+        EXPECT_LE(SkColorGetG(blurred_pixel), static_cast<uint32>(128));
+      }
+
+      i++;
+    }
+  }
+}
+
+// Make sure that when shifting a bitmap without any shift parameters,
+// the end result is close enough to the original (rounding errors
+// notwithstanding).
+TEST(ImageOperations, CreateHSLShiftedBitmapToSame) {
+  int src_w = 4, src_h = 4;
+  SkBitmap src;
+  src.setConfig(SkBitmap::kARGB_8888_Config, src_w, src_h);
+  src.allocPixels();
+
+  for (int y = 0, i = 0; y < src_h; y++) {
+    for (int x = 0; x < src_w; x++) {
+      *src.getAddr32(x, y) = SkColorSetARGB(i + 128 % 255,
+          i + 128 % 255, i + 64 % 255, i + 0 % 255);
+      i++;
+    }
+  }
+
+  skia::HSL hsl = { -1, -1, -1 };
+
+  SkBitmap shifted = skia::ImageOperations::CreateHSLShiftedBitmap(src, hsl);
+
+  SkAutoLockPixels src_lock(src);
+  SkAutoLockPixels shifted_lock(shifted);
+
+  for (int y = 0; y < src_w; y++) {
+    for (int x = 0; x < src_h; x++) {
+      SkColor src_pixel = *src.getAddr32(x, y);
+      SkColor shifted_pixel = *shifted.getAddr32(x, y);
+      EXPECT_TRUE(ColorsClose(src_pixel, shifted_pixel));
+    }
+  }
+}
+
+// Shift a blue bitmap to red.
+TEST(ImageOperations, CreateHSLShiftedBitmapHueOnly) {
+  int src_w = 16, src_h = 16;
+  SkBitmap src;
+  src.setConfig(SkBitmap::kARGB_8888_Config, src_w, src_h);
+  src.allocPixels();
+
+  for (int y = 0, i = 0; y < src_h; y++) {
+    for (int x = 0; x < src_w; x++) {
+      *src.getAddr32(x, y) = SkColorSetARGB(255, 0, 0, i % 255);
+      i++;
+    }
+  }
+
+  // Shift to red.
+  skia::HSL hsl = { 0, -1, -1 };
+
+  SkBitmap shifted = skia::ImageOperations::CreateHSLShiftedBitmap(src, hsl);
+
+  SkAutoLockPixels src_lock(src);
+  SkAutoLockPixels shifted_lock(shifted);
+
+  for (int y = 0, i = 0; y < src_h; y++) {
+    for (int x = 0; x < src_w; x++) {
+      EXPECT_TRUE(ColorsClose(*shifted.getAddr32(x, y),
+                              SkColorSetARGB(255, i % 255, 0, 0)));
+      i++;
+    }
+  }
+}
+
+// Test our cropping.
+TEST(ImageOperations, CreateCroppedBitmap) {
+  int src_w = 16, src_h = 16;
+  SkBitmap src;
+  FillDataToBitmap(src_w, src_h, &src);
+
+  SkBitmap cropped = skia::ImageOperations::CreateTiledBitmap(src, 4, 4,
+                                                              8, 8);
+  ASSERT_EQ(8, cropped.width());
+  ASSERT_EQ(8, cropped.height());
+
+  SkAutoLockPixels src_lock(src);
+  SkAutoLockPixels cropped_lock(cropped);
+  for (int y = 4; y < 12; y++) {
+    for (int x = 4; x < 12; x++) {
+      EXPECT_EQ(*src.getAddr32(x, y),
+                *cropped.getAddr32(x - 4, y - 4));
+    }
+  }
+}
+
+// Test whether our cropping correctly wraps across image boundaries.
+TEST(ImageOperations, CreateCroppedBitmapWrapping) {
+  int src_w = 16, src_h = 16;
+  SkBitmap src;
+  FillDataToBitmap(src_w, src_h, &src);
+
+  SkBitmap cropped = skia::ImageOperations::CreateTiledBitmap(
+      src, src_w / 2, src_h / 2, src_w, src_h);
+  ASSERT_EQ(src_w, cropped.width());
+  ASSERT_EQ(src_h, cropped.height());
+
+  SkAutoLockPixels src_lock(src);
+  SkAutoLockPixels cropped_lock(cropped);
+  for (int y = 0; y < src_h; y++) {
+    for (int x = 0; x < src_w; x++) {
+      EXPECT_EQ(*src.getAddr32(x, y),
+                *cropped.getAddr32((x + src_w / 2) % src_w,
+                                   (y + src_h / 2) % src_h));
+    }
+  }
+}
+
+TEST(ImageOperations, DownsampleByTwo) {
+  // Use an odd-sized bitmap to make sure the edge cases where there isn't a
+  // 2x2 block of pixels is handled correctly.
+  // Here's the ARGB example
+  //
+  //    50% transparent green             opaque 50% blue           white
+  //        80008000                         FF000080              FFFFFFFF
+  //
+  //    50% transparent red               opaque 50% gray           black
+  //        80800000                         80808080              FF000000
+  //
+  //         black                            white                50% gray
+  //        FF000000                         FFFFFFFF              FF808080
+  //
+  // The result of this computation should be:
+  //        A0404040  FF808080
+  //        FF808080  FF808080
+  SkBitmap input;
+  input.setConfig(SkBitmap::kARGB_8888_Config, 3, 3);
+  input.allocPixels();
+
+  // The color order may be different, but we don't care (the channels are
+  // trated the same).
+  *input.getAddr32(0, 0) = 0x80008000;
+  *input.getAddr32(1, 0) = 0xFF000080;
+  *input.getAddr32(2, 0) = 0xFFFFFFFF;
+  *input.getAddr32(0, 1) = 0x80800000;
+  *input.getAddr32(1, 1) = 0x80808080;
+  *input.getAddr32(2, 1) = 0xFF000000;
+  *input.getAddr32(0, 2) = 0xFF000000;
+  *input.getAddr32(1, 2) = 0xFFFFFFFF;
+  *input.getAddr32(2, 2) = 0xFF808080;
+
+  SkBitmap result = skia::ImageOperations::DownsampleByTwo(input);
+  EXPECT_EQ(2, result.width());
+  EXPECT_EQ(2, result.height());
+
+  // Some of the values are off-by-one due to rounding.
+  SkAutoLockPixels lock(result);
+  EXPECT_EQ(0x9f404040, *result.getAddr32(0, 0));
+  EXPECT_EQ(0xFF7f7f7f, *result.getAddr32(1, 0));
+  EXPECT_EQ(0xFF7f7f7f, *result.getAddr32(0, 1));
+  EXPECT_EQ(0xFF808080, *result.getAddr32(1, 1));
+}
+
+// Test edge cases for DownsampleByTwo.
+TEST(ImageOperations, DownsampleByTwoSmall) {
+  SkPMColor reference = 0xFF4080FF;
+
+  // Test a 1x1 bitmap.
+  SkBitmap one_by_one;
+  one_by_one.setConfig(SkBitmap::kARGB_8888_Config, 1, 1);
+  one_by_one.allocPixels();
+  *one_by_one.getAddr32(0, 0) = reference;
+  SkBitmap result = skia::ImageOperations::DownsampleByTwo(one_by_one);
+  SkAutoLockPixels lock1(result);
+  EXPECT_EQ(1, result.width());
+  EXPECT_EQ(1, result.height());
+  EXPECT_EQ(reference, *result.getAddr32(0, 0));
+
+  // Test an n by 1 bitmap.
+  SkBitmap one_by_n;
+  one_by_n.setConfig(SkBitmap::kARGB_8888_Config, 300, 1);
+  one_by_n.allocPixels();
+  result = skia::ImageOperations::DownsampleByTwo(one_by_n);
+  SkAutoLockPixels lock2(result);
+  EXPECT_EQ(300, result.width());
+  EXPECT_EQ(1, result.height());
+
+  // Test a 1 by n bitmap.
+  SkBitmap n_by_one;
+  n_by_one.setConfig(SkBitmap::kARGB_8888_Config, 1, 300);
+  n_by_one.allocPixels();
+  result = skia::ImageOperations::DownsampleByTwo(n_by_one);
+  SkAutoLockPixels lock3(result);
+  EXPECT_EQ(1, result.width());
+  EXPECT_EQ(300, result.height());
+
+  // Test an empty bitmap
+  SkBitmap empty;
+  result = skia::ImageOperations::DownsampleByTwo(empty);
+  EXPECT_TRUE(result.isNull());
+  EXPECT_EQ(0, result.width());
+  EXPECT_EQ(0, result.height());
+}
+
+// Here we assume DownsampleByTwo works correctly (it's tested above) and
+// just make sure that the 
+TEST(ImageOperations, DownsampleByTwoUntilSize) {
+  // First make sure a "too small" bitmap doesn't get modified at all.
+  SkBitmap too_small;
+  too_small.setConfig(SkBitmap::kARGB_8888_Config, 10, 10);
+  too_small.allocPixels();
+  SkBitmap result = skia::ImageOperations::DownsampleByTwoUntilSize(
+      too_small, 16, 16);
+  EXPECT_EQ(10, result.width());
+  EXPECT_EQ(10, result.height());
+
+  // Now make sure giving it a 0x0 target returns something reasonable.
+  result = skia::ImageOperations::DownsampleByTwoUntilSize(too_small, 0, 0);
+  EXPECT_EQ(1, result.width());
+  EXPECT_EQ(1, result.height());
+
+  // Test multiple steps of downsampling.
+  SkBitmap large;
+  large.setConfig(SkBitmap::kARGB_8888_Config, 100, 43);
+  large.allocPixels();
+  result = skia::ImageOperations::DownsampleByTwoUntilSize(large, 6, 6);
+
+  // The result should be divided in half 100x43 -> 50x22 -> 25x11
+  EXPECT_EQ(25, result.width());
+  EXPECT_EQ(11, result.height());
+}
diff --git a/skia/ext/skia_utils.cc b/skia/ext/skia_utils.cc
index c95054d..84a003b 100644
--- a/skia/ext/skia_utils.cc
+++ b/skia/ext/skia_utils.cc
@@ -1,10 +1,9 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2006-2008 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 "skia/ext/skia_utils.h"
 #include "third_party/skia/include/core/SkColorPriv.h"
-#include "third_party/skia/include/core/SkShader.h"
 #include "third_party/skia/include/effects/SkGradientShader.h"
 
 namespace skia {
@@ -22,5 +21,150 @@ SkShader* CreateGradientShader(int start_point,
       grad_points, grad_colors, NULL, 2, SkShader::kRepeat_TileMode);
 }
 
+// Helper function for HSLToSKColor.
+static inline double calcHue(double temp1, double temp2, double hueVal) {
+  if (hueVal < 0.0)
+    hueVal++;
+  else if (hueVal > 1.0)
+    hueVal--;
+
+  if (hueVal * 6.0 < 1.0)
+    return temp1 + (temp2 - temp1) * hueVal * 6.0;
+  if (hueVal * 2.0 < 1.0)
+    return temp2;
+  if (hueVal * 3.0 < 2.0)
+    return temp1 + (temp2 - temp1) * (2.0 / 3.0 - hueVal) * 6.0;
+
+  return temp1;
+}
+
+SkColor HSLToSkColor(U8CPU alpha, HSL hsl) {
+  double hue = hsl.h;
+  double saturation = hsl.s;
+  double lightness = hsl.l;
+
+  // If there's no color, we don't care about hue and can do everything based
+  // on brightness.
+  if (!saturation) {
+    U8CPU light;
+
+    if (lightness < 0)
+      light = 0;
+    else if (lightness >= SK_Scalar1)
+      light = 255;
+    else
+      light = SkDoubleToFixed(lightness) >> 8;
+
+    return SkColorSetARGB(alpha, light, light, light);
+  }
+
+  double temp2 = (lightness < 0.5) ?
+      lightness * (1.0 + saturation) :
+      lightness + saturation - (lightness * saturation);
+  double temp1 = 2.0 * lightness - temp2;
+
+  double rh = calcHue(temp1, temp2, hue + 1.0 / 3.0);
+  double gh = calcHue(temp1, temp2, hue);
+  double bh = calcHue(temp1, temp2, hue - 1.0 / 3.0);
+
+  return SkColorSetARGB(alpha,
+      static_cast<int>(rh * 255),
+      static_cast<int>(gh * 255),
+      static_cast<int>(bh * 255));
+}
+
+void SkColorToHSL(SkColor c, HSL& hsl) {
+  double r = SkColorGetR(c) / 255.0;
+  double g = SkColorGetG(c) / 255.0;
+  double b = SkColorGetB(c) / 255.0;
+
+  double h, s, l;
+
+  double vmax = r > g ? r : g;
+  vmax = vmax > b ? vmax : b;
+  double vmin = r < g ? r : g;
+  vmin = vmin < b ? vmin : b;
+  double delta = vmax - vmin;
+
+  l = (vmax + vmin) / 2;
+
+  if (delta == 0) {
+    h = 0;
+    s = 0;
+  } else {
+    if (l < 0.5)
+      s = delta / (vmax + vmin);
+    else
+      s = delta / (2 - vmax - vmin);
+
+    double dr = (((vmax - r) / 6.0) + (delta / 2.0)) / delta;
+    double dg = (((vmax - g) / 6.0) + (delta / 2.0)) / delta;
+    double db = (((vmax - b) / 6.0) + (delta / 2.0)) / delta;
+
+    if (r == vmax)
+      h = db - dg;
+    else if (g == vmax)
+      h = (1.0 / 3.0) + dr - db;
+    else if (b == vmax)
+      h = (2.0 / 3.0) + dg - dr;
+
+    if (h < 0) h += 1;
+    if (h > 1) h -= 1;
+  }
+
+  hsl.h = h;
+  hsl.s = s;
+  hsl.l = l;
+}
+
+SkColor HSLShift(SkColor color, HSL shift) {
+  HSL hsl;
+  int alpha = SkColorGetA(color);
+  SkColorToHSL(color, hsl);
+
+  // Replace the hue with the tint's hue.
+  if (shift.h >= 0)
+    hsl.h = shift.h;
+
+  // Change the saturation.
+  if (shift.s >= 0) {
+    if (shift.s <= 0.5) {
+      hsl.s *= shift.s * 2.0;
+    } else {
+      hsl.s = hsl.s + (1.0 - hsl.s) *
+        ((shift.s - 0.5) * 2.0);
+    }
+  }
+
+  SkColor result = HSLToSkColor(alpha, hsl);
+
+  // Lightness shifts in the style of popular image editors aren't
+  // actually represented in HSL - the L value does have some effect
+  // on saturation.
+  if (shift.l >= 0) {
+    double r = static_cast<double>SkColorGetR(result);
+    double g = static_cast<double>SkColorGetG(result);
+    double b = static_cast<double>SkColorGetB(result);
+
+    if (shift.l <= 0.5) {
+      r *= (shift.l * 2.0);
+      g *= (shift.l * 2.0);
+      b *= (shift.l * 2.0);
+    } else {
+      r = (r + (255.0 - r) * ((shift.l - 0.5) * 2.0));
+      g = (g + (255.0 - g) * ((shift.l - 0.5) * 2.0));
+      b = (b + (255.0 - b) * ((shift.l - 0.5) * 2.0));
+    }
+
+    return SkColorSetARGB(alpha, 
+                          static_cast<int>(r),
+                          static_cast<int>(g),
+                          static_cast<int>(b));
+  } else {
+    return result;
+  }
+}
+
+
 }  // namespace skia
 
diff --git a/skia/ext/skia_utils.h b/skia/ext/skia_utils.h
index 52d9d62..769d9d4 100644
--- a/skia/ext/skia_utils.h
+++ b/skia/ext/skia_utils.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2006-2008 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.
 
@@ -6,11 +6,16 @@
 #define SKIA_EXT_SKIA_UTILS_H_
 
 #include "third_party/skia/include/core/SkColor.h"
-
-class SkShader;
+#include "third_party/skia/include/core/SkShader.h"
 
 namespace skia {
 
+struct HSL {
+  double h;
+  double s;
+  double l;
+};
+
 // Creates a vertical gradient shader. The caller owns the shader.
 // Example usage to avoid leaks:
 //   paint.setShader(gfx::CreateGradientShader(0, 10, red, blue))->safeUnref();
@@ -21,6 +26,29 @@ SkShader* CreateGradientShader(int start_point,
                                int end_point,
                                SkColor start_color,
                                SkColor end_color);
+
+// Convert an SkColor to a HSL value.
+void SkColorToHSL(SkColor c, HSL& hsl);
+
+// Convert a HSL color to an SkColor.
+SkColor HSLToSkColor(U8CPU alpha, HSL hsl);
+
+// HSL-Shift an SkColor. The shift values are in the range of 0-1, with the 
+// option to specify -1 for 'no change'. The shift values are defined as:
+// hsl_shift[0] (hue): The absolute hue value - 0 and 1 map
+//    to 0 and 360 on the hue color wheel (red).
+// hsl_shift[1] (saturation): A saturation shift, with the
+//    following key values:
+//    0 = remove all color.
+//    0.5 = leave unchanged.
+//    1 = fully saturate the image.
+// hsl_shift[2] (lightness): A lightness shift, with the
+//    following key values:
+//    0 = remove all lightness (make all pixels black).
+//    0.5 = leave unchanged.
+//    1 = full lightness (make all pixels white).
+SkColor HSLShift(SkColor color, skia::HSL shift);
+
 }  // namespace skia
 
 #endif  // SKIA_EXT_SKIA_UTILS_H_
diff --git a/skia/ext/skia_utils_unittest.cc b/skia/ext/skia_utils_unittest.cc
new file mode 100644
index 0000000..3b590b4
--- /dev/null
+++ b/skia/ext/skia_utils_unittest.cc
@@ -0,0 +1,42 @@
+// Copyright (c) 2006-2008 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 <stdlib.h>
+
+#include "skia/ext/skia_utils.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "third_party/skia/include/core/SkColorPriv.h"
+
+TEST(SkiaUtils, SkColorToHSLRed) {
+  SkColor red = SkColorSetARGB(255, 255, 0, 0);
+  skia::HSL hsl = { 0, 0, 0 };
+  skia::SkColorToHSL(red, hsl);
+  EXPECT_EQ(hsl.h, 0);
+  EXPECT_EQ(hsl.s, 1);
+  EXPECT_EQ(hsl.l, 0.5);
+}
+
+TEST(SkiaUtils, SkColorToHSLGrey) {
+  SkColor red = SkColorSetARGB(255, 128, 128, 128);
+  skia::HSL hsl = { 0, 0, 0 };
+  skia::SkColorToHSL(red, hsl);
+  EXPECT_EQ(hsl.h, 0);
+  EXPECT_EQ(hsl.s, 0);
+  EXPECT_EQ(static_cast<int>(hsl.l * 100),
+            static_cast<int>(0.5 * 100));  // Accurate to two decimal places.
+}
+
+TEST(SkiaUtils, HSLToSkColorWithAlpha) {
+  SkColor red = SkColorSetARGB(128, 255, 0, 0);
+
+  skia::HSL hsl = { 0, 1, 0.5 };
+
+  SkColor result = skia::HSLToSkColor(128, hsl);
+  EXPECT_EQ(SkColorGetA(red), SkColorGetA(result));
+  EXPECT_EQ(SkColorGetR(red), SkColorGetR(result));
+  EXPECT_EQ(SkColorGetG(red), SkColorGetG(result));
+  EXPECT_EQ(SkColorGetB(red), SkColorGetB(result));
+}
+