Work around for nexus 6 TexSubImage issue

BUG=skia:

Review URL: https://codereview.chromium.org/1173203005

include/gpu/GrCaps.h

@@ -133,6 +133,9 @@ public:
     bool textureBarrierSupport() const { return fTextureBarrierSupport; }
 
     bool useDrawInsteadOfClear() const { return fUseDrawInsteadOfClear; }
+    bool useDrawInsteadOfPartialTextureWrite() const {
+        return fUseDrawInsteadOfPartialTextureWrite;
+    }
 
     /**
      * Indicates the capabilities of the fixed function blend unit.
@@ -220,18 +223,19 @@ protected:
 
     SkAutoTUnref<GrShaderCaps>    fShaderCaps;
 
-    bool fNPOTTextureTileSupport        : 1;
-    bool fMipMapSupport                 : 1;
-    bool fTwoSidedStencilSupport        : 1;
-    bool fStencilWrapOpsSupport         : 1;
-    bool fDiscardRenderTargetSupport    : 1;
-    bool fReuseScratchTextures          : 1;
-    bool fGpuTracingSupport             : 1;
-    bool fCompressedTexSubImageSupport  : 1;
-    bool fOversizedStencilSupport       : 1;
-    bool fTextureBarrierSupport         : 1;
+    bool fNPOTTextureTileSupport                : 1;
+    bool fMipMapSupport                         : 1;
+    bool fTwoSidedStencilSupport                : 1;
+    bool fStencilWrapOpsSupport                 : 1;
+    bool fDiscardRenderTargetSupport            : 1;
+    bool fReuseScratchTextures                  : 1;
+    bool fGpuTracingSupport                     : 1;
+    bool fCompressedTexSubImageSupport          : 1;
+    bool fOversizedStencilSupport               : 1;
+    bool fTextureBarrierSupport                 : 1;
     // Driver workaround
-    bool fUseDrawInsteadOfClear         : 1;
+    bool fUseDrawInsteadOfClear                 : 1;
+    bool fUseDrawInsteadOfPartialTextureWrite   : 1;
 
     BlendEquationSupport fBlendEquationSupport;
     uint32_t fAdvBlendEqBlacklist;

include/gpu/GrContextOptions.h

@@ -17,7 +17,8 @@ struct GrContextOptions {
         , fMaxTextureSizeOverride(SK_MaxS32)
         , fMinTextureSizeOverride(0)
         , fSuppressDualSourceBlending(false)
-        , fGeometryBufferMapThreshold(-1) {}
+        , fGeometryBufferMapThreshold(-1)
+        , fUseDrawInsteadOfPartialTextureWrite(false) {}
 
     // EXPERIMENTAL
     // May be removed in the future, or may become standard depending
@@ -39,6 +40,9 @@ struct GrContextOptions {
         buffers to CPU memory in order to update them.  A value of -1 means the GrContext should
         deduce the optimal value for this platform. */
     int  fGeometryBufferMapThreshold;
+
+    /** some gpus have problems with partial texture writes */
+    bool fUseDrawInsteadOfPartialTextureWrite;
 };
 
 #endif

src/gpu/GrCaps.cpp

@@ -109,6 +109,7 @@ GrCaps::GrCaps(const GrContextOptions& options) {
     fSupressPrints = options.fSuppressPrints;
     fDrawPathMasksToCompressedTextureSupport = options.fDrawPathToCompressedTexture;
     fGeometryBufferMapThreshold = options.fGeometryBufferMapThreshold;
+    fUseDrawInsteadOfPartialTextureWrite = options.fUseDrawInsteadOfPartialTextureWrite;
 }
 
 void GrCaps::applyOptionsOverrides(const GrContextOptions& options) {
@@ -150,6 +151,8 @@ SkString GrCaps::dump() const {
     r.appendf("Oversized Stencil Support          : %s\n", gNY[fOversizedStencilSupport]);
     r.appendf("Texture Barrier Support            : %s\n", gNY[fTextureBarrierSupport]);
     r.appendf("Draw Instead of Clear [workaround] : %s\n", gNY[fUseDrawInsteadOfClear]);
+    r.appendf("Draw Instead of TexSubImage [workaround] : %s\n",
+              gNY[fUseDrawInsteadOfPartialTextureWrite]);
     if (this->advancedBlendEquationSupport()) {
         r.appendf("Advanced Blend Equation Blacklist  : 0x%x\n", fAdvBlendEqBlacklist);
     }

src/gpu/GrContext.cpp

@@ -334,7 +334,9 @@ bool GrContext::writeSurfacePixels(GrSurface* surface,
     {
         GrTexture* texture = NULL;
         if (!(kUnpremul_PixelOpsFlag & pixelOpsFlags) && (texture = surface->asTexture()) &&
-            fGpu->canWriteTexturePixels(texture, srcConfig)) {
+            fGpu->canWriteTexturePixels(texture, srcConfig) &&
+            (!fCaps->useDrawInsteadOfPartialTextureWrite() ||
+             (width == texture->width() && height == texture->height()))) {
 
             if (!(kDontFlush_PixelOpsFlag & pixelOpsFlags) &&
                 surface->surfacePriv().hasPendingIO()) {

src/gpu/gl/GrGLCaps.cpp

@@ -421,6 +421,10 @@ void GrGLCaps::init(const GrContextOptions& contextOptions,
         fUseDrawInsteadOfClear = true;
     }
 
+    if (kAdreno4xx_GrGLRenderer == ctxInfo.renderer()) {
+        fUseDrawInsteadOfPartialTextureWrite = true;
+    }
+
     if (kGL_GrGLStandard == standard) {
         // ARB allows mixed size FBO attachments, EXT does not.
         if (ctxInfo.version() >= GR_GL_VER(3, 0) ||