Clean up pdf/draw_utils/shadow.h.

Forward declare some classes and move bits not needed into the header
into shadow.cc.

Change-Id: I1b54966a2e1619be64951a58e6ac6ca0a8b705ee
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1696387
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#676464}

pdf/draw_utils/shadow.cc

@@ -6,14 +6,18 @@
 
 #include <math.h>
 #include <stddef.h>
-#include <stdint.h>
+
 #include <algorithm>
-#include <vector>
 
 #include "base/logging.h"
-#include "base/numerics/safe_math.h"
+#include "ppapi/cpp/image_data.h"
+#include "ppapi/cpp/rect.h"
 
 namespace chrome_pdf {
+namespace draw_utils {
+
+constexpr uint8_t kOpaqueAlpha = 0xFF;
+constexpr uint8_t kTransparentAlpha = 0x00;
 
 inline uint8_t GetBlue(const uint32_t& pixel) {
   return static_cast<uint8_t>(pixel & 0xFF);
@@ -169,4 +173,5 @@ void DrawShadow(pp::ImageData* image,
   PaintShadow(image, rc.Intersect(clip_rc), shadow_rc, matrix);
 }
 
+}  // namespace draw_utils
 }  // namespace chrome_pdf

pdf/draw_utils/shadow.h

@@ -9,13 +9,13 @@
 
 #include <vector>
 
-#include "ppapi/cpp/image_data.h"
-#include "ppapi/cpp/rect.h"
+namespace pp {
+class ImageData;
+class Rect;
+}  // namespace pp
 
 namespace chrome_pdf {
-
-const uint8_t kOpaqueAlpha = 0xFF;
-const uint8_t kTransparentAlpha = 0x00;
+namespace draw_utils {
 
 // Shadow Matrix contains matrix for shadow rendering. To reduce amount of
 // calculations user may choose to cache matrix and reuse it if nothing changed.
@@ -52,6 +52,7 @@ void DrawShadow(pp::ImageData* image,
                 const pp::Rect& clip_rc,
                 const ShadowMatrix& matrix);
 
+}  // namespace draw_utils
 }  // namespace chrome_pdf
 
 #endif  // PDF_DRAW_UTILS_SHADOW_H_

pdf/pdfium/pdfium_engine.cc

@@ -3367,8 +3367,8 @@ void PDFiumEngine::DrawPageShadow(const pp::Rect& page_rc,
   depth = static_cast<uint32_t>(depth * 1.5) + 1;
 
   // We need to check depth only to verify our copy of shadow matrix is correct.
-  if (!page_shadow_.get() || page_shadow_->depth() != depth) {
-    page_shadow_ = std::make_unique<ShadowMatrix>(
+  if (!page_shadow_ || page_shadow_->depth() != depth) {
+    page_shadow_ = std::make_unique<draw_utils::ShadowMatrix>(
         depth, factor, client_->GetBackgroundColor());
   }
 

pdf/pdfium/pdfium_engine.h

@@ -38,7 +38,10 @@
 namespace chrome_pdf {
 
 class PDFiumDocument;
+
+namespace draw_utils {
 class ShadowMatrix;
+}
 
 class PDFiumEngine : public PDFEngine,
                      public DocumentLoader::Client,
@@ -649,7 +652,7 @@ class PDFiumEngine : public PDFEngine,
   base::TimeDelta progressive_paint_timeout_;
 
   // Shadow matrix for generating the page shadow bitmap.
-  std::unique_ptr<ShadowMatrix> page_shadow_;
+  std::unique_ptr<draw_utils::ShadowMatrix> page_shadow_;
 
   // While true, the document try to be opened and parsed after download each
   // part. Else the document will be opened and parsed only on finish of