Rename `iRotate` to `rotation`

Use Google C++ style naming. The build rules specify -Wshadow, so there
should be a warning if this rename collides with a pre-existing
`rotation` variable. Also rename some `rotate` variables to `rotation`
for consistency.

Change-Id: I0962f7db1815e95219219bbb47692c8fc2ec1ee4
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/132211
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fpdfapi/page/cpdf_page.cpp b/core/fpdfapi/page/cpdf_page.cpp
index 272a394..795fd19 100644
--- a/core/fpdfapi/page/cpdf_page.cpp
+++ b/core/fpdfapi/page/cpdf_page.cpp
@@ -108,21 +108,22 @@
 
 std::optional<CFX_PointF> CPDF_Page::DeviceToPage(
     const FX_RECT& rect,
-    int rotate,
+    int rotation,
     const CFX_PointF& device_point) const {
-  CFX_Matrix page2device = GetDisplayMatrix(rect, rotate);
+  CFX_Matrix page2device = GetDisplayMatrix(rect, rotation);
   return page2device.GetInverse().Transform(device_point);
 }
 
 std::optional<CFX_PointF> CPDF_Page::PageToDevice(
     const FX_RECT& rect,
-    int rotate,
+    int rotation,
     const CFX_PointF& page_point) const {
-  CFX_Matrix page2device = GetDisplayMatrix(rect, rotate);
+  CFX_Matrix page2device = GetDisplayMatrix(rect, rotation);
   return page2device.Transform(page_point);
 }
 
-CFX_Matrix CPDF_Page::GetDisplayMatrix(const FX_RECT& rect, int iRotate) const {
+CFX_Matrix CPDF_Page::GetDisplayMatrix(const FX_RECT& rect,
+                                       int rotation) const {
   if (page_size_.width == 0 || page_size_.height == 0) {
     return CFX_Matrix();
   }
@@ -133,14 +134,14 @@
   float y1 = 0;
   float x2 = 0;
   float y2 = 0;
-  iRotate %= 4;
+  rotation %= 4;
   // This code implicitly inverts the y-axis to account for page coordinates
   // pointing up and bitmap coordinates pointing down. (x0, y0) is the base
   // point, (x1, y1) is that point translated on y and (x2, y2) is the point
-  // translated on x. On iRotate = 0, y0 is rect.bottom and the translation
+  // translated on x. On rotation = 0, y0 is rect.bottom and the translation
   // to get y1 is performed as negative. This results in the desired
   // transformation.
-  switch (iRotate) {
+  switch (rotation) {
     case 0:
       x0 = rect.left;
       y0 = rect.bottom;
@@ -183,8 +184,8 @@
 int CPDF_Page::GetPageRotation() const {
   RetainPtr<const CPDF_Object> pRotate =
       GetPageAttr(pdfium::page_object::kRotate);
-  int rotate = pRotate ? (pRotate->GetInteger() / 90) % 4 : 0;
-  return (rotate < 0) ? (rotate + 4) : rotate;
+  int rotation = pRotate ? (pRotate->GetInteger() / 90) % 4 : 0;
+  return (rotation < 0) ? (rotation + 4) : rotation;
 }
 
 RetainPtr<CPDF_Array> CPDF_Page::GetOrCreateAnnotsArray() {
diff --git a/core/fpdfapi/page/cpdf_page.h b/core/fpdfapi/page/cpdf_page.h
index 7e14511..25da545 100644
--- a/core/fpdfapi/page/cpdf_page.h
+++ b/core/fpdfapi/page/cpdf_page.h
@@ -57,14 +57,14 @@
   CPDF_Document* GetDocument() const override;
   float GetPageWidth() const override;
   float GetPageHeight() const override;
-  CFX_Matrix GetDisplayMatrix(const FX_RECT& rect, int iRotate) const override;
+  CFX_Matrix GetDisplayMatrix(const FX_RECT& rect, int rotation) const override;
   std::optional<CFX_PointF> DeviceToPage(
       const FX_RECT& rect,
-      int rotate,
+      int rotation,
       const CFX_PointF& device_point) const override;
   std::optional<CFX_PointF> PageToDevice(
       const FX_RECT& rect,
-      int rotate,
+      int rotation,
       const CFX_PointF& page_point) const override;
 
   // CPDF_PageObjectHolder:
diff --git a/core/fpdfapi/page/ipdf_page.h b/core/fpdfapi/page/ipdf_page.h
index a37155f..c693ac4 100644
--- a/core/fpdfapi/page/ipdf_page.h
+++ b/core/fpdfapi/page/ipdf_page.h
@@ -34,16 +34,16 @@
   virtual float GetPageWidth() const = 0;
   virtual float GetPageHeight() const = 0;
   virtual CFX_Matrix GetDisplayMatrix(const FX_RECT& rect,
-                                      int iRotate) const = 0;
+                                      int rotation) const = 0;
 
   virtual std::optional<CFX_PointF> DeviceToPage(
       const FX_RECT& rect,
-      int rotate,
+      int rotation,
       const CFX_PointF& device_point) const = 0;
 
   virtual std::optional<CFX_PointF> PageToDevice(
       const FX_RECT& rect,
-      int rotate,
+      int rotation,
       const CFX_PointF& page_point) const = 0;
 };
 
diff --git a/fpdfsdk/fpdfxfa/cpdfxfa_page.cpp b/fpdfsdk/fpdfxfa/cpdfxfa_page.cpp
index 283ea84..09061ec 100644
--- a/fpdfsdk/fpdfxfa/cpdfxfa_page.cpp
+++ b/fpdfsdk/fpdfxfa/cpdfxfa_page.cpp
@@ -186,32 +186,32 @@
 
 std::optional<CFX_PointF> CPDFXFA_Page::DeviceToPage(
     const FX_RECT& rect,
-    int rotate,
+    int rotation,
     const CFX_PointF& device_point) const {
   CXFA_FFPageView* pPageView = GetXFAPageView();
   if (!pdfpage_ && !pPageView) {
     return std::nullopt;
   }
 
-  CFX_Matrix page2device = GetDisplayMatrix(rect, rotate);
+  CFX_Matrix page2device = GetDisplayMatrix(rect, rotation);
   return page2device.GetInverse().Transform(device_point);
 }
 
 std::optional<CFX_PointF> CPDFXFA_Page::PageToDevice(
     const FX_RECT& rect,
-    int rotate,
+    int rotation,
     const CFX_PointF& page_point) const {
   CXFA_FFPageView* pPageView = GetXFAPageView();
   if (!pdfpage_ && !pPageView) {
     return std::nullopt;
   }
 
-  CFX_Matrix page2device = GetDisplayMatrix(rect, rotate);
+  CFX_Matrix page2device = GetDisplayMatrix(rect, rotation);
   return page2device.Transform(page_point);
 }
 
 CFX_Matrix CPDFXFA_Page::GetDisplayMatrix(const FX_RECT& rect,
-                                          int iRotate) const {
+                                          int rotation) const {
   CXFA_FFPageView* pPageView = GetXFAPageView();
   if (!pdfpage_ && !pPageView) {
     return CFX_Matrix();
@@ -223,12 +223,12 @@
     case FormType::kAcroForm:
     case FormType::kXFAForeground:
       if (pdfpage_) {
-        return pdfpage_->GetDisplayMatrix(rect, iRotate);
+        return pdfpage_->GetDisplayMatrix(rect, rotation);
       }
       [[fallthrough]];
     case FormType::kXFAFull:
       if (pPageView) {
-        return pPageView->GetDisplayMatrix(rect, iRotate);
+        return pPageView->GetDisplayMatrix(rect, rotation);
       }
       break;
   }
diff --git a/fpdfsdk/fpdfxfa/cpdfxfa_page.h b/fpdfsdk/fpdfxfa/cpdfxfa_page.h
index b358123..3c761ff 100644
--- a/fpdfsdk/fpdfxfa/cpdfxfa_page.h
+++ b/fpdfsdk/fpdfxfa/cpdfxfa_page.h
@@ -32,14 +32,14 @@
   CPDF_Document* GetDocument() const override;
   float GetPageWidth() const override;
   float GetPageHeight() const override;
-  CFX_Matrix GetDisplayMatrix(const FX_RECT& rect, int iRotate) const override;
+  CFX_Matrix GetDisplayMatrix(const FX_RECT& rect, int rotation) const override;
   std::optional<CFX_PointF> DeviceToPage(
       const FX_RECT& rect,
-      int rotate,
+      int rotation,
       const CFX_PointF& device_point) const override;
   std::optional<CFX_PointF> PageToDevice(
       const FX_RECT& rect,
-      int rotate,
+      int rotation,
       const CFX_PointF& page_point) const override;
 
   bool LoadPage();
diff --git a/xfa/fxfa/cxfa_ffpageview.cpp b/xfa/fxfa/cxfa_ffpageview.cpp
index 9f2bea9..4fff68b 100644
--- a/xfa/fxfa/cxfa_ffpageview.cpp
+++ b/xfa/fxfa/cxfa_ffpageview.cpp
@@ -30,20 +30,20 @@
 
 CFX_Matrix GetPageMatrix(const CFX_RectF& docPageRect,
                          const FX_RECT& devicePageRect,
-                         int32_t iRotate) {
-  DCHECK(iRotate >= 0);
-  DCHECK(iRotate <= 3);
+                         int32_t rotation) {
+  DCHECK(rotation >= 0);
+  DCHECK(rotation <= 3);
 
   CFX_Matrix m;
-  if (iRotate == 0 || iRotate == 2) {
+  if (rotation == 0 || rotation == 2) {
     m.a *= (float)devicePageRect.Width() / docPageRect.width;
     m.d *= (float)devicePageRect.Height() / docPageRect.height;
   } else {
     m.a *= (float)devicePageRect.Height() / docPageRect.width;
     m.d *= (float)devicePageRect.Width() / docPageRect.height;
   }
-  m.Rotate(iRotate * 1.57079632675f);
-  switch (iRotate) {
+  m.Rotate(rotation * 1.57079632675f);
+  switch (rotation) {
     case 0:
       m.e = devicePageRect.left;
       m.f = devicePageRect.top;
@@ -263,13 +263,13 @@
 }
 
 CFX_Matrix CXFA_FFPageView::GetDisplayMatrix(const FX_RECT& rtDisp,
-                                             int32_t iRotate) const {
+                                             int32_t rotation) const {
   auto* pItem = GetLayoutItem();
   if (!pItem) {
     return CFX_Matrix();
   }
 
-  return GetPageMatrix(CFX_RectF(0, 0, pItem->GetPageSize()), rtDisp, iRotate);
+  return GetPageMatrix(CFX_RectF(0, 0, pItem->GetPageSize()), rtDisp, rotation);
 }
 
 CXFA_FFWidget::IteratorIface* CXFA_FFPageView::CreateGCedTraverseWidgetIterator(
diff --git a/xfa/fxfa/cxfa_ffpageview.h b/xfa/fxfa/cxfa_ffpageview.h
index b6a09c4..1e73447 100644
--- a/xfa/fxfa/cxfa_ffpageview.h
+++ b/xfa/fxfa/cxfa_ffpageview.h
@@ -35,7 +35,7 @@
 
   CXFA_FFDocView* GetDocView() const;
   CFX_RectF GetPageViewRect() const;
-  CFX_Matrix GetDisplayMatrix(const FX_RECT& rtDisp, int32_t iRotate) const;
+  CFX_Matrix GetDisplayMatrix(const FX_RECT& rtDisp, int32_t rotation) const;
 
   // This always returns a non-null iterator from the gc heap.
   CXFA_FFWidget::IteratorIface* CreateGCedTraverseWidgetIterator(
diff --git a/xfa/fxfa/cxfa_ffwidget.cpp b/xfa/fxfa/cxfa_ffwidget.cpp
index 2840785..bd60b5a 100644
--- a/xfa/fxfa/cxfa_ffwidget.cpp
+++ b/xfa/fxfa/cxfa_ffwidget.cpp
@@ -522,14 +522,14 @@
 }
 
 CFX_Matrix CXFA_FFWidget::GetRotateMatrix() {
-  int32_t iRotate = node_->GetRotate();
-  if (!iRotate) {
+  int32_t rotation = node_->GetRotate();
+  if (rotation == 0) {
     return CFX_Matrix();
   }
 
   CFX_RectF rcWidget = GetRectWithoutRotate();
   CFX_Matrix mt;
-  switch (iRotate) {
+  switch (rotation) {
     case 90:
       mt.a = 0;
       mt.b = -1;