diff --git a/image/encoders/bmp/nsBMPEncoder.cpp b/image/encoders/bmp/nsBMPEncoder.cpp
index 0f6a5614cf4..71d60677f4c 100644
--- a/image/encoders/bmp/nsBMPEncoder.cpp
+++ b/image/encoders/bmp/nsBMPEncoder.cpp
@@ -206,7 +206,7 @@ nsBMPEncoder::AddImageFrame(const uint8_t* aData,
     }
   } else if (aInputFormat == INPUT_FORMAT_RGBA) {
     // simple RGBA, no conversion needed
-    for (int32_t y = 0; y < mBMPInfoHeader.height; y ++) {
+    for (int32_t y = 0; y < mBMPInfoHeader.height; y++) {
       if (mBMPInfoHeader.bpp == 24) {
         EncodeImageDataRow24(row);
       } else {
@@ -215,7 +215,7 @@ nsBMPEncoder::AddImageFrame(const uint8_t* aData,
     }
   } else if (aInputFormat == INPUT_FORMAT_RGB) {
     // simple RGB, no conversion needed
-    for (int32_t y = 0; y < mBMPInfoHeader.height; y ++) {
+    for (int32_t y = 0; y < mBMPInfoHeader.height; y++) {
       if (mBMPInfoHeader.bpp == 24) {
         EncodeImageDataRow24(&aData[y * aStride]);
       } else {
@@ -700,7 +700,7 @@ nsBMPEncoder::EncodeImageDataRow24(const uint8_t* aData)
 void
 nsBMPEncoder::EncodeImageDataRow32(const uint8_t* aData)
 {
-  for (int32_t x = 0; x < mBMPInfoHeader.width; x ++) {
+  for (int32_t x = 0; x < mBMPInfoHeader.width; x++) {
     uint32_t pos = x * BytesPerPixel(mBMPInfoHeader.bpp);
     SetPixel32(mImageBufferCurr, aData[pos], aData[pos + 1],
                aData[pos + 2], aData[pos + 3]);
@@ -708,7 +708,7 @@ nsBMPEncoder::EncodeImageDataRow32(const uint8_t* aData)
   }
 
   for (uint32_t x = 0; x < PaddingBytes(mBMPInfoHeader.bpp,
-                                        mBMPInfoHeader.width); x ++) {
+                                        mBMPInfoHeader.width); x++) {
     *mImageBufferCurr++ = 0;
   }
 }
diff --git a/image/encoders/bmp/nsBMPEncoder.h b/image/encoders/bmp/nsBMPEncoder.h
index 5fa202e0b62..5abfd50dec8 100644
--- a/image/encoders/bmp/nsBMPEncoder.h
+++ b/image/encoders/bmp/nsBMPEncoder.h
@@ -2,6 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#ifndef mozilla_image_encoders_bmp_nsBMPEncoder_h
+#define mozilla_image_encoders_bmp_nsBMPEncoder_h
+
 #include "mozilla/Attributes.h"
 #include "mozilla/ReentrantMonitor.h"
 
@@ -91,3 +94,5 @@ protected:
   nsCOMPtr<nsIEventTarget> mCallbackTarget;
   uint32_t mNotifyThreshold;
 };
+
+#endif // mozilla_image_encoders_bmp_nsBMPEncoder_h
diff --git a/image/encoders/ico/nsICOEncoder.h b/image/encoders/ico/nsICOEncoder.h
index e4ad20bab28..ffa5cb138d4 100644
--- a/image/encoders/ico/nsICOEncoder.h
+++ b/image/encoders/ico/nsICOEncoder.h
@@ -2,6 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#ifndef mozilla_image_encoders_ico_nsICOEncoder_h
+#define mozilla_image_encoders_ico_nsICOEncoder_h
+
 #include "mozilla/Attributes.h"
 #include "mozilla/ReentrantMonitor.h"
 
@@ -96,3 +99,5 @@ protected:
   nsCOMPtr<nsIEventTarget> mCallbackTarget;
   uint32_t mNotifyThreshold;
 };
+
+#endif // mozilla_image_encoders_ico_nsICOEncoder_h
diff --git a/image/encoders/jpeg/nsJPEGEncoder.h b/image/encoders/jpeg/nsJPEGEncoder.h
index 3616b3b871a..2bcf5c2f3ed 100644
--- a/image/encoders/jpeg/nsJPEGEncoder.h
+++ b/image/encoders/jpeg/nsJPEGEncoder.h
@@ -3,6 +3,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#ifndef mozilla_image_encoders_jpeg_nsJPEGEncoder_h
+#define mozilla_image_encoders_jpeg_nsJPEGEncoder_h
+
 #include "imgIEncoder.h"
 
 #include "mozilla/ReentrantMonitor.h"
@@ -77,3 +80,5 @@ protected:
   // that only one thread dispatches a callback for each call to AsyncWait.
   ReentrantMonitor mReentrantMonitor;
 };
+
+#endif // mozilla_image_encoders_jpeg_nsJPEGEncoder_h
diff --git a/image/encoders/png/nsPNGEncoder.cpp b/image/encoders/png/nsPNGEncoder.cpp
index d21ea4ebdba..141e5418442 100644
--- a/image/encoders/png/nsPNGEncoder.cpp
+++ b/image/encoders/png/nsPNGEncoder.cpp
@@ -36,8 +36,7 @@ nsPNGEncoder::nsPNGEncoder() : mPNG(nullptr), mPNGinfo(nullptr),
                                mCallbackTarget(nullptr), mNotifyThreshold(0),
                                mReentrantMonitor(
                                               "nsPNGEncoder.mReentrantMonitor")
-{
-}
+{ }
 
 nsPNGEncoder::~nsPNGEncoder()
 {
@@ -291,7 +290,7 @@ nsPNGEncoder::AddImageFrame(const uint8_t* aData,
     // PNG requires RGBA with post-multiplied alpha, so we need to
     // convert
     uint8_t* row = new uint8_t[aWidth * 4];
-    for (uint32_t y = 0; y < aHeight; y ++) {
+    for (uint32_t y = 0; y < aHeight; y++) {
       ConvertHostARGBRow(&aData[y * aStride], row, aWidth, useTransparency);
       png_write_row(mPNG, row);
     }
@@ -300,7 +299,7 @@ nsPNGEncoder::AddImageFrame(const uint8_t* aData,
   } else if (aInputFormat == INPUT_FORMAT_RGBA && !useTransparency) {
     // RBGA, but we need to strip the alpha
     uint8_t* row = new uint8_t[aWidth * 4];
-    for (uint32_t y = 0; y < aHeight; y ++) {
+    for (uint32_t y = 0; y < aHeight; y++) {
       StripAlpha(&aData[y * aStride], row, aWidth);
       png_write_row(mPNG, row);
     }
@@ -309,7 +308,7 @@ nsPNGEncoder::AddImageFrame(const uint8_t* aData,
   } else if (aInputFormat == INPUT_FORMAT_RGB ||
              aInputFormat == INPUT_FORMAT_RGBA) {
     // simple RBG(A), no conversion needed
-    for (uint32_t y = 0; y < aHeight; y ++) {
+    for (uint32_t y = 0; y < aHeight; y++) {
       png_write_row(mPNG, (uint8_t*)&aData[y * aStride]);
     }
 
@@ -655,7 +654,7 @@ nsPNGEncoder::ConvertHostARGBRow(const uint8_t* aSrc, uint8_t* aDest,
                                  bool aUseTransparency)
 {
   uint32_t pixelStride = aUseTransparency ? 4 : 3;
-  for (uint32_t x = 0; x < aPixelWidth; x ++) {
+  for (uint32_t x = 0; x < aPixelWidth; x++) {
     const uint32_t& pixelIn = ((const uint32_t*)(aSrc))[x];
     uint8_t* pixelOut = &aDest[x * pixelStride];
 
@@ -684,7 +683,7 @@ void
 nsPNGEncoder::StripAlpha(const uint8_t* aSrc, uint8_t* aDest,
                           uint32_t aPixelWidth)
 {
-  for (uint32_t x = 0; x < aPixelWidth; x ++) {
+  for (uint32_t x = 0; x < aPixelWidth; x++) {
     const uint8_t* pixelIn = &aSrc[x * 4];
     uint8_t* pixelOut = &aDest[x * 3];
     pixelOut[0] = pixelIn[0];