Add initial pipeline for decompressors

src/utils/SkTextureCompressor.cpp

Index: src/utils/SkTextureCompressor.cpp
diff --git a/src/utils/SkTextureCompressor.cpp b/src/utils/SkTextureCompressor.cpp
index 30fd3072d5b67e8dab3e9981ebef631509893e7e..801328642ff301cd4cad88232373c67316273378 100644
--- a/src/utils/SkTextureCompressor.cpp
+++ b/src/utils/SkTextureCompressor.cpp
@@ -20,15 +20,16 @@
 
 namespace SkTextureCompressor {
 
-void GetBlockDimensions(Format format, int* dimX, int* dimY) {
+void GetBlockDimensions(Format format, int* dimX, int* dimY, bool matchSpec) {
     if (NULL == dimX || NULL == dimY) {
         return;
     }
 
-    if (SkTextureCompressorGetPlatformDims(format, dimX, dimY)) {
+    if (!matchSpec && SkTextureCompressorGetPlatformDims(format, dimX, dimY)) {
         return;
     }
 
+    // No specialized arguments, return the dimensions as they are in the spec.
     switch(format) {
         // These formats are 64 bits per 4x4 block.
         default:
@@ -50,7 +51,8 @@ void GetBlockDimensions(Format format, int* dimX, int* dimY) {
 
 int GetCompressedDataSize(Format fmt, int width, int height) {
     int dimX, dimY;
-    GetBlockDimensions(fmt, &dimX, &dimY);
+    GetBlockDimensions(fmt, &dimX, &dimY, true);
+
     int encodedBlockSize = 0;
             
     switch (fmt) {
@@ -159,4 +161,30 @@ SkBlitter* CreateBlitterForFormat(int width, int height, void* compressedBuffer,
     return NULL;
 }
 
+bool DecompressBufferFromFormat(uint8_t* dst, int dstRowBytes, const uint8_t* src,
+                                int width, int height, Format format) {
+    int dimX, dimY;
+    GetBlockDimensions(format, &dimX, &dimY, true);
+
+    if (width < 0 || ((width % dimX) != 0) || height < 0 || ((height % dimY) != 0)) {
+        return false;
+    }
+
+    switch(format) {
+        case kLATC_Format:
+            DecompressLATC(dst, dstRowBytes, src, width, height);
+            return true;
+
+        case kR11_EAC_Format:
+            DecompressR11EAC(dst, dstRowBytes, src, width, height);
+            return true;
+
+        case kASTC_12x12_Format:
+            // TODO(krajcevski) .. right now just fall through and return false.
+            return false;
+    }
+
+    return false;
+}
+
 }  // namespace SkTextureCompressor